Continued from EC 1.14.15 to EC 1.14.18
EC 1.14.19.51 to EC 1.14.19.79
Accepted name: stearoyl-CoA 9-desaturase
Reaction: stearoyl-CoA + 2 ferrocytochrome b5 + O2 + 2 H+ = oleoyl-CoA + 2 ferricytochrome b5 + 2 H2O
Other name(s): δ9-desaturase; acyl-CoA desaturase; fatty acid desaturase; stearoyl-CoA, hydrogen-donor:oxygen oxidoreductase
Systematic name: stearoyl-CoA,ferrocytochrome-b5:oxygen oxidoreductase (9,10-dehydrogenating)
Comments: An iron protein. The rat liver enzyme is an enzyme system involving cytochrome b5 and EC 1.6.2.2, cytochrome-b5 reductase. The ferricytochrome b5 produced is reduced by NADH and cytochrome-b5 reductase (EC 1.6.2.2).
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9014-34-0
References:
1. Fulco, A.J. and Bloch, K. Cofactor requirements for the formation of δ9-unsaturated fatty acids in Mycobacterium phlei. J. Biol. Chem. 239 (1964) 993-997. [PMID: 14167617]
2. Oshino, N., Imai, Y. and Sato, R. Electron-transfer mechanism associated with fatty acid desaturation catalyzed by liver microsomes. Biochim. Biophys. Acta 128 (1966) 13-27. [PMID: 4382040]
3. Oshino, N., Imai, Y. and Sato, R. A function of cytochrome b5 in fatty acid desaturation by rat liver microsomes. J. Biochem. (Tokyo) 69 (1971) 155-167. [PMID: 5543646]
4. Strittmatter, P., Sputz, L., Corcoran, D., Rogers, M.J., Setlow, B. and Redline, R. Purification and properties of rat liver microsomal stearyl coenzyme A desaturase. Proc. Natl. Acad. Sci. USA 71 (1974) 4565-4569. [PMID: 4373719]
Accepted name: stearoyl-[acyl-carrier-protein] 9-desaturase
Reaction: stearoyl-[acyl-carrier protein] + 2 reduced ferredoxin [iron-sulfur] cluster + O2 + 2 H+ = oleoyl-[acyl-carrier protein] + 2 oxidized ferredoxin [iron-sulfur] cluster + 2 H2O
Other name(s): stearyl acyl carrier protein desaturase; stearyl-ACP desaturase; acyl-[acyl-carrier-protein] desaturase; acyl-[acyl-carrier protein],hydrogen-donor:oxygen oxidoreductase
Systematic name: stearoyl-[acyl-carrier protein],reduced ferredoxin:oxygen oxidoreductase (9,10 cis-dehydrogenating)
Comments: The enzyme is found in the lumen of plastids, where de novo biosynthesis of fatty acids occurs, and acts on freshly synthesized saturated fatty acids that are still linked to acyl-carrier protein. The enzyme determines the position of the double bond by its distance from the carboxylic acid end of the fatty acid. It also acts on palmitoyl-[acyl-carrier-protein] [4,5].
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 37256-86-3
References:
1. Jaworski, J.G. and Stumpf, P.K. Fat metabolism in higher plants. Properties of a soluble stearyl-acyl carrier protein desaturase from maturing Carthamus tinctorius. Arch. Biochem. Biophys. 162 (1974) 158-165. [PMID: 4831331]
2. Nagai, J. and Bloch, K. Enzymatic desaturation of stearyl acyl carrier protein. J. Biol. Chem. 243 (1968) 4626-4633. [PMID: 4300868]
3. Shanklin, J. and Somerville, C. Stearoyl-acyl-carrier-protein desaturase from higher plants is structurally unrelated to the animal and fungal homologs. Proc. Natl. Acad. Sci. USA 88 (1991) 2510-2514. [PMID: 2006187]
4. Cahoon, E.B., Lindqvist, Y., Schneider, G. and Shanklin, J. Redesign of soluble fatty acid desaturases from plants for altered substrate specificity and double bond position. Proc. Natl. Acad. Sci. USA 94 (1997) 4872-4877. [PMID: 9144157]
5. Cao, Y., Xian, M., Yang, J., Xu, X., Liu, W. and Li, L. Heterologous expression of stearoyl-acyl carrier protein desaturase (S-ACP-DES) from Arabidopsis thaliana in Escherichia coli. Protein Expr. Purif. 69 (2010) 209-214. [PMID: 19716420]
Accepted name: acyl-CoA 6-desaturase
Reaction: (1) linoleoyl-CoA + 2 ferrocytochrome b5 + O2 + 2 H+ = γ-linolenoyl-CoA + 2 ferricytochrome b5 + 2 H2O
(2) α-linolenoyl-CoA + 2 ferrocytochrome b5 + O2 + 2 H+ = stearidonoyl-CoA + 2 ferricytochrome b5 + 2 H2O
Other name(s): Δ6-desaturase; Δ6-fatty acyl-CoA desaturase; Δ6-acyl CoA desaturase; fatty acid Δ6-desaturase; fatty acid 6-desaturase; linoleate desaturase; linoleic desaturase; linoleic acid desaturase; linoleoyl CoA desaturase; linoleoyl-coenzyme A desaturase; long-chain fatty acid Δ6-desaturase; linoleoyl-CoA,hydrogen-donor:oxygen oxidoreductase; linoleoyl-CoA desaturase; FADS2 (gene name)
Systematic name: acyl-CoA,ferrocytochrome b5:oxygen oxidoreductase (6,7 cis-dehydrogenating)
Comments: An iron protein. The enzyme introduces a cis double bond at carbon 6 of acyl-CoAs. It is a front-end desaturase, introducing the new double bond between a pre-existing double bond and the carboxyl-end of the fatty acid. The human enzyme has a broad substrate range. It also acts on palmitoyl-CoA, generating sapienoyl-CoA [4], and on (9Z,12Z,15Z,18Z,21Z)-tetracosa-9,12,15,18,21-pentaenoyl-CoA, converting it to (6Z,9Z,12Z,15Z,18Z,21Z)-tetracosa-6,9,12,15,18,21-hexaenoyl-CoA as part of a pathway that produces docosahexaenoate [3]. The enzyme contains a cytochrome b5 domain that is assumed to act in vivo as the electron donor to the active site of the desaturase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 9082-66-0
References:
1. Okayasu, T., Nagao, M., Ishibashi, T. and Imai, Y. Purification and partial characterization of linoleoyl-CoA desaturase from rat liver microsomes. Arch. Biochem. Biophys. 206 (1981) 21-28. [PMID: 7212717]
2. Cho, H.P., Nakamura, M.T. and Clarke, S.D. Cloning, expression, and nutritional regulation of the mammalian Δ-6 desaturase. J. Biol. Chem. 274 (1999) 471-477. [PMID: 9867867]
3. Sprecher, H. Metabolism of highly unsaturated n-3 and n-6 fatty acids. Biochim. Biophys. Acta 1486 (2000) 219-231. [PMID: 10903473]
4. Ge, L., Gordon, J.S., Hsuan, C., Stenn, K. and Prouty, S.M. Identification of the Δ-6 desaturase of human sebaceous glands: expression and enzyme activity. J. Invest. Dermatol. 120 (2003) 707-714. [PMID: 12713571]
5. Domergue, F., Abbadi, A., Zähringer, U., Moreau, H. and Heinz, E. In vivo characterization of the first acyl-CoA Δ6-desaturase from a member of the plant kingdom, the microalga Ostreococcus tauri. Biochem. J. 389 (2005) 483-490. [PMID: 15769252]
Accepted name: acyl-lipid (11-3)-desaturase
Reaction: (1) an (11Z,14Z)-icosa-11,14-dienoyl-[glycerolipid] + 2 ferrocytochrome b5 + O2 + 2 H+ = an (8Z,11Z,14Z)-icosa-8,11,14-trienoyl-[glycerolipid] + 2 ferricytochrome b5 + 2 H2O
(2) an (11Z,14Z,17Z)-icosa-11,14,17-trienoyl-[glycerolipid] + 2 ferrocytochrome b5 + O2 + 2 H+ = an (8Z,11Z,14Z,17Z)-icosa-8,11,14,17-tetraenoyl-[glycerolipid] + 2 ferricytochrome b5 + 2 H2O
Glossary: (8Z,11Z,14Z)-icosa-8,11,14-trienoate = di-homo-γ-linolenate
Other name(s): acyl-lipid 8-desaturase; Δ8 fatty acid desaturase; Δ8-desaturase; Δ8-fatty-acid desaturase; efd1 (gene name); D8Des (gene name); phytosphinganine,hydrogen donor:oxygen Δ8-oxidoreductase (incorrect); SLD
Systematic name: acyl-lipid,ferrocytochrome b5:oxygen oxidoreductase [(11-3),(11-2) cis-dehydrogenating]
Comments: The enzyme, characterized from the protist Euglena gracilis [1] and the microalga Rebecca salina [2], introduces a cis double bond at the 8-position in 20-carbon fatty acids that are incorporated into a glycerolipid and have an existing Δ11 desaturation. The enzyme is a front-end desaturase, introducing the new double bond between the pre-existing double bond and the carboxyl-end of the fatty acid. It contains a cytochrome b5 domain that acts as the direct electron donor to the active site of the desaturase, and does not require an external cytochrome. Involved in alternative pathways for the biosynthesis of the polyunsaturated fatty acids arachidonate and icosapentaenoate.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Wallis, J.G. and Browse, J. The Δ8-desaturase of Euglena gracilis: an alternate pathway for synthesis of 20-carbon polyunsaturated fatty acids. Arch. Biochem. Biophys. 365 (1999) 307-316. [PMID: 10328826]
2. Zhou, X.R., Robert, S.S., Petrie, J.R., Frampton, D.M., Mansour, M.P., Blackburn, S.I., Nichols, P.D., Green, A.G. and Singh, S.P. Isolation and characterization of genes from the marine microalga Pavlova salina encoding three front-end desaturases involved in docosahexaenoic acid biosynthesis. Phytochemistry 68 (2007) 785-796. [PMID: 17291553]
Accepted name: acyl-CoA 11-(Z)-desaturase
Reaction: an acyl-CoA + 2 ferrocytochrome b5 + O2 + 2 H+ = an (11Z)-enoyl-CoA + 2 ferricytochrome b5 + 2 H2O
Other name(s): Δ11 desaturase; fatty acid Δ11-desaturase; TpDESN; Cro-PG; Δ11 fatty acid desaturase; Z/E11-desaturase; Δ11-palmitoyl-CoA desaturase; acyl-CoA,hydrogen donor:oxygen Δ11-oxidoreductase; Δ11-fatty-acid desaturase
Systematic name: acyl-CoA,ferrocytochrome b5:oxygen oxidoreductase (11,12 cis-dehydrogenating)
Comments: The enzyme introduces a cis double bond at position C-11 of saturated fatty acyl-CoAs. In moths the enzyme participates in the biosynthesis of their sex pheromones. The enzyme from the marine microalga Thalassiosira pseudonana is specific for palmitoyl-CoA (16:0) [4], that from the leafroller moth Choristoneura rosaceana desaturates myristoyl-CoA (14:0) [5], while that from the moth Spodoptera littoralis accepts both substrates [1]. The enzyme contains three histidine boxes that are conserved in all desaturases [2]. It is membrane-bound, and contains a cytochrome b5-like domain at the N-terminus that serves as the electron donor for the active site of the desaturase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Martinez, T., Fabrias, G. and Camps, F. Sex pheromone biosynthetic pathway in Spodoptera littoralis and its activation by a neurohormone. J. Biol. Chem. 265 (1990) 1381-1387. [PMID: 2295634]
2. Rodriguez, F., Hallahan, D.L., Pickett, J.A. and Camps, F. Characterization of the Δ11-palmitoyl-CoA-desaturase from Spodoptera littoralis (Lepidoptera:Noctuidae). Insect Biochem. Mol. Biol. 22 (1992) 143-148.
3. Navarro, I., Font, I., Fabrias, G. and Camps, F. Stereospecificity of the (E)- and (Z)-11 myristoyl desaturases in the biosynthesis of Spodoptera littoralis sex pheromone. J. Am. Chem. Soc. 119 (1997) 11335-11336.
4. Tonon, T., Harvey, D., Qing, R., Li, Y., Larson, T.R. and Graham, I.A. Identification of a fatty acid Δ11-desaturase from the microalga Thalassiosira pseudonana. FEBS Lett. 563 (2004) 28-34. [PMID: 15063718]
5. Hao, G., O'Connor, M., Liu, W. and Roelofs, W.L. Characterization of Z/E11- and Z9-desaturases from the obliquebanded leafroller moth, Choristoneura rosaceana. J. Insect Sci. 2:26 (2002) 1-7. [PMID: 15455060]
Accepted name: acyl-CoA (9+3)-desaturase
Reaction: (1) oleoyl-CoA + 2 ferrocytochrome b5 + O2 + 2 H+ = linoleoyl-CoA + 2 ferricytochrome b5 + 2 H2O
(2) palmitoleoyl-CoA + 2 ferrocytochrome b5 + O2 + 2 H+ = (9Z,12Z)-hexadeca-9,12-dienoyl-CoA + 2 ferricytochrome b5 + 2 H2O
Glossary: oleoyl-CoA = cis-octadec-9-enoyl-CoA = (9Z)-octadec-9-enoyl-CoA = 18:1 cis-9 = 18:1(n-9)
linoleoyl-CoA = cis,cis-octadeca-9,12-dienoyl-CoA = (9Z,12Z)-octadeca-9,12-dienoyl-CoA = 18:2(n-6)
palmitoleoyl-CoA = (9Z)-hexadec-9-enoyl-CoA
Other name(s): oleoyl-CoA 12-desaturase; Δ12 fatty acid desaturase; Δ12(ω6)-desaturase; oleoyl-CoA Δ12 desaturase; Δ12 desaturase; Δ12-desaturase; Δ12-fatty-acid desaturase; acyl-CoA,hydrogen donor:oxygen Δ12-oxidoreductase
Systematic name: acyl-CoA,ferrocytochrome b5:oxygen oxidoreductase (12,13 cis-dehydrogenating)
Comments: This microsomal enzyme introduces a cis double bond at position 12 of fatty-acyl-CoAs that contain a cis double bond at position 9. When acting on 19:1Δ10 fatty acyl-CoA the enzyme from the pathogenic protozoan Trypanosoma brucei introduces the new double bond at position 13, indicating that the new double bond is introduced three carbons from the existing cis double bond, towards the methyl-end of the fatty acid. Requires cytochrome b5 as the electron donor [4].
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Borgeson, C.E., de Renobales, M. and Blomquist, G.J. Characterization of the Δ12 desaturase in the American cockroach, Periplaneta americana: the nature of the substrate. Biochim. Biophys. Acta 1047 (1990) 135-140. [PMID: 2248971]
2. Lomascolo, A., Dubreucq, E. and Galzy, P. Study of the Δ12-desaturase system of Lipomyces starkeyi. Lipids 31 (1996) 253-259. [PMID: 8900454]
3. Tocher, D.R., Leaver, M.J. and Hodgson, P.A. Recent advances in the biochemistry and molecular biology of fatty acyl desaturases. Prog. Lipid Res. 37 (1998) 73-117. [PMID: 9829122]
4. Petrini, G.A., Altabe, S.G. and Uttaro, A.D. Trypanosoma brucei oleate desaturase may use a cytochrome b5-like domain in another desaturase as an electron donor. Eur. J. Biochem. 271 (2004) 1079-1086. [PMID: 15009186]
[EC 1.14.19.7 Transferred entry: (S)-2-hydroxypropylphosphonic acid epoxidase. Now EC 1.11.1.23, (S)-2-hydroxypropylphosphonic acid epoxidase. (EC 1.14.19.7 created 2011, deleted 2014)]
Accepted name: pentalenolactone synthase
Reaction: pentalenolactone F + O2 + 2 reduced ferredoxin + 2 H+ = pentalenolactone + 2 oxidized ferredoxin + 2 H2O
For diagram of reaction click here.
Glossary: pentalenolactone F = (1R,4aR,6aS,9aR)-8,8-dimethyl-2-oxo-4,4a,6a,8,9-hexahydrospiro[oxirane-2,1-pentaleno[1,6a-c]pyran]-5-carboxylic acid
pentalenolactone = (1R,4aR,6aR,7S,9aS)-7,8-dimethyl-2-oxo-4,4a,6a,7-tetrahydrospiro[oxirane-2,1-pentaleno[1,6a-c]pyran]-5-carboxylic acid
Other name(s): penM (gene name); pntM (gene name)
Systematic name: pentalenolactone-reduced-ferredoxin:oxygen oxidoreductase (pentalenolactone forming)
Comments: A heme-thiolate protein (P-450). Isolated from the bacteria Streptomyces exfoliatus and Streptomyces arenae.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:
References:
1. Zhu, D., Seo, M.J., Ikeda, H. and Cane, D.E. Genome mining in streptomyces. Discovery of an unprecedented P450-catalyzed oxidative rearrangement that is the final step in the biosynthesis of pentalenolactone. J. Am. Chem. Soc. 133 (2011) 2128-2131. [PMID: 21284395]
Accepted name: tryptophan 7-halogenase
Reaction: L-tryptophan + FADH2 + chloride + O2 + H+ = 7-chloro-L-tryptophan + FAD + 2 H2O
For diagram of reaction click here.
Other name(s): prnA (gene name); rebH (gene name); ktzQ (gene name)
Systematic name: L-tryptophan:FADH2 oxidoreductase (7-halogenating)
Comments: A flavin-dependent halogenase. The enzyme from the bacterium Lechevalieria aerocolonigenes catalyses the initial step in the biosynthesis of rebeccamycin [2]. It utilizes molecular oxygen to oxidize the FADH2 cofactor, giving C4a-hydroperoxyflavin, which then reacts with chloride to produce a hypochlorite ion. The latter reacts with an active site lysine to generate a chloramine, which chlorinates the substrate. Also acts on bromide ion. cf. EC 1.14.19.58, tryptophan 5-halogenase, and EC 1.14.19.59, tryptophan 6-halogenase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:
References:
1. Dong, C., Kotzsch, A., Dorward, M., van Pee, K.H. and Naismith, J.H. Crystallization and X-ray diffraction of a halogenating enzyme, tryptophan 7-halogenase, from Pseudomonas fluorescens. Acta Crystallogr. D Biol. Crystallogr. 60 (2004) 1438-1440. [PMID: 15272170]
2. Yeh, E., Garneau, S. and Walsh, C.T. Robust in vitro activity of RebF and RebH, a two-component reductase/halogenase, generating 7-chlorotryptophan during rebeccamycin biosynthesis. Proc. Natl. Acad. Sci. USA 102 (2005) 3960-3965. [PMID: 15743914]
3. Bitto, E., Huang, Y., Bingman, C.A., Singh, S., Thorson, J.S. and Phillips Jr., G.N. The structure of flavin-dependent tryptophan 7-halogenase RebH. Proteins Struct. Funct. Genet. 70 (2008) 289-293.
4. Heemstra, J.R., Jr. and Walsh, C.T. Tandem action of the O2- and FADH2-dependent halogenases KtzQ and KtzR produce 6,7-dichlorotryptophan for kutzneride assembly. J. Am. Chem. Soc. 130 (2008) 14024-14025. [PMID: 18828589]
Accepted name: icosanoyl-CoA 5-desaturase
Reaction: icosanoyl-CoA + 2 ferrocytochrome b5 + O2 + 2 H+ = (Z)-icos-5-enoyl-CoA + 2 ferricytochrome b5 + 2 H2O
Other name(s): acyl-CoA Δ5-desaturase (ambiguous)
Systematic name: icosanoyl-CoA,ferrocytochrome b5:oxygen oxidoreductase (5,6 cis-dehydrogenating)
Comments: The enzyme, characterized from the plant Limnanthes douglasii (meadowfoam), is involved in the biosynthesis of (5Z)-icos-5-enoate, an unusual monounsaturated fatty acid that makes up to 60% of the total fatty acids in Limnanthes sp. seed oil. The enzyme only acts on saturated fatty acids.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Cahoon, E.B., Marillia, E.F., Stecca, K.L., Hall, S.E., Taylor, D.C. and Kinney, A.J. Production of fatty acid components of meadowfoam oil in somatic soybean embryos. Plant Physiol. 124 (2000) 243-251. [PMID: 10982439]
Accepted name: palmitoyl-[acyl-carrier-protein] 4-desaturase
Reaction: palmitoyl-[acyl-carrier protein] + reduced acceptor + O2 = (4Z)-hexadec-4-enoyl-[acyl-carrier protein] + acceptor + 2 H2O
Other name(s): Δ4-palmitoyl-[acyl carrier protein] desaturase
Systematic name: palmitoyl-[acyl-carrier protein],reduced acceptor:oxygen oxidoreductase (4,5 cis-dehydrogenating)
Comments: The enzyme, characterized from the plant Coriandrum sativum (coriander), is involved in biosynthesis of petroselinate [(6Z)-octadec-6-enoate], which is formed by elongation of (4Z)-hexadec-4-enoate.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Cahoon, E.B., Shanklin, J. and Ohlrogge, J.B. Expression of a coriander desaturase results in petroselinic acid production in transgenic tobacco. Proc. Natl. Acad. Sci. USA 89 (1992) 11184-11188. [PMID: 1454797]
2. Cahoon, E.B. and Ohlrogge, J.B. Metabolic evidence for the involvement of a Δ4-palmitoyl-acyl carrier protein desaturase in petroselinic acid synthesis in coriander endosperm and transgenic tobacco cells. Plant Physiol. 104 (1994) 827-837. [PMID: 12232129]
Accepted name: acyl-lipid ω-(9-4) desaturase
Reaction: (1) linoleoyl-[glycerolipid] + 2 ferrocytochrome b5 + O2 + 2 H+ = pinolenoyl-[glycerolipid] + 2 ferricytochrome b5 + 2 H2O
(2) α-linolenoyl-[glycerolipid] + 2 ferrocytochrome b5 + O2 + 2 H+ = coniferonoyl-[glycerolipid] + 2 ferricytochrome b5 + 2 H2O
Glossary: taxoleate = (5Z,9Z)-octadeca-5,9-dienoate
pinolenoate = (5Z,9Z,12Z)-octadeca-5,9,12-trienoate
coniferonate = (5Z,9Z,12Z,15Z)-octadeca-5,9,12,15-tetraenoate
Other name(s): acyl-lipid ω-13 desaturase; acyl-lipid 7-desaturase (ambiguous)
Systematic name: acyl-[glycerolipid],ferrocytochrome b5:oxygen oxidoreductase [ω(9-4),ω(9-5) cis-dehydrogenating]
Comments: The enzyme, characterized from the green alga Chlamydomonas reinhardtii, is a front-end desaturase that introduces a cis double bond in ω9 unsaturated C18 or C20 fatty acids incorporated into lipids, at a position 4 carbon atoms from the existing ω9 bond, towards the carboxy end of the fatty acid (at the ω13 position). When acting on 20:2Δ(11,14) and 20:3Δ(11,14,17) substrates it introduces the new double bond between carbons 7 and 8. The enzyme contains a cytochrome b5 domain that acts as the direct electron donor for the active site of the desaturase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Kajikawa, M., Yamato, K.T., Kohzu, Y., Shoji, S., Matsui, K., Tanaka, Y., Sakai, Y. and Fukuzawa, H. A front-end desaturase from Chlamydomonas reinhardtii produces pinolenic and coniferonic acids by ω13 desaturation in methylotrophic yeast and tobacco. Plant Cell Physiol 47 (2006) 64-73. [PMID: 16267098]
Accepted name: acyl-CoA 15-desaturase
Reaction: (9Z,12Z)-hexadeca-9,12-dienoyl-CoA + reduced acceptor + O2 = (9Z,12Z,15Z)-hexadeca-9,12,15-trienoyl-CoA + acceptor + 2 H2O
Other name(s): DES3 (gene name)
Systematic name: acyl-CoA,reduced acceptor:oxygen oxidoreductase (15,16 cis-dehydrogenating)
Comments: The enzyme, characterized from the the plant Sorghum bicolor, is involved in the biosynthesis of sorgoleone, an allelopathic compound produced in root hair cells. The enzyme inserts a cis double bond at carbon 15. When acting on its natural substrate, (9Z,12Z)-hexadeca-9,12-dienoyl-CoA, it produces a product with a terminal double bond.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Pan, Z., Rimando, A.M., Baerson, S.R., Fishbein, M. and Duke, S.O. Functional characterization of desaturases involved in the formation of the terminal double bond of an unusual 16:3Δ(9,12,15) fatty acid isolated from Sorghum bicolor root hairs. J. Biol. Chem. 282 (2007) 4326-4335. [PMID: 17178719]
Accepted name: linoleoyl-lipid Δ9 conjugase
Reaction: a linoleoyl-[glycerolipid] + reduced acceptor + O2 = an (8E,10E,12Z)-octadeca-8,10,12-trienoyl-[glycerolipid] + acceptor + 2 H2O
Glossary: calendate = (8E,10E,12Z)-octadeca-8,10,12-trienoate
Systematic name: linoleoyl-lipid,reduced acceptor:oxygen 8,11-allylic oxidase (8E,10E-forming)
Comments: The enzyme, characterized from the plant Calendula officinalis, converts a single cis double bond at position 9 of fatty acids incorporated into glycerolipids into two conjugated trans double bonds at positions 8 and 10.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Qiu, X., Reed, D.W., Hong, H., MacKenzie, S.L. and Covello, P.S. Identification and analysis of a gene from Calendula officinalis encoding a fatty acid conjugase. Plant Physiol. 125 (2001) 847-855. [PMID: 11161042]
2. Cahoon, E.B., Ripp, K.G., Hall, S.E. and Kinney, A.J. Formation of conjugated Δ8,Δ10-double bonds by Δ12-oleic-acid desaturase-related enzymes: biosynthetic origin of calendic acid. J. Biol. Chem. 276 (2001) 2637-2643. [PMID: 11067856]
Accepted name: (11Z)-hexadec-11-enoyl-CoA conjugase
Reaction: (11Z)-hexadec-11-enoyl-CoA + reduced acceptor + O2 = (10E,12Z)-hexadeca-10,12-dienoyl-CoA + acceptor + 2 H2O
Other name(s): Bmpgdesat1 (gene name)
Systematic name: (11Z)-hexadec-11-enoyl-CoA,reduced acceptor:oxygen 10,13-allylic oxidase (10E,12E-forming)
Comments: The enzyme, characterized from the silk moth Bombyx mori, catalyses a step in the pathway for the biosynthesis of bombykol, a sex pheromone produced by the moth. The enzyme converts a single cis double bond at position 11 of (11Z)-hexadec-11-enoyl-CoA into conjugated 10 trans and 12 cis double bonds. Prior to catalysing this reaction, the enzyme catalyses the introduction of the cis bond in position 11 (cf. EC 1.14.19.5, acyl-CoA 11-desaturase).
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Moto, K., Suzuki, M.G., Hull, J.J., Kurata, R., Takahashi, S., Yamamoto, M., Okano, K., Imai, K., Ando, T. and Matsumoto, S. Involvement of a bifunctional fatty-acyl desaturase in the biosynthesis of the silkmoth, Bombyx mori, sex pheromone. Proc. Natl. Acad. Sci. USA 101 (2004) 8631-8636. [PMID: 15173596]
Accepted name: linoleoyl-lipid Δ12 conjugase (11E,13Z-forming)
Reaction: a linoleoyl-[glycerolipid] + 2 ferrocytochrome b5 + O2 + 2 H+ = a (9Z,11E,13Z)-octadeca-9,11,13-trienoyl-[glycerolipid] + 2 ferricytochrome b5 + 2 H2O
Glossary: punicate = (9Z,11E,13Z)-octadeca-9,11,13-trienoate
linoleate = (9Z,12Z)-octadeca-9,12-dienoate
Other name(s): Fac (gene name)
Systematic name: linoleoyl-lipid,ferrocytochrome-b5:oxygen 11,14 allylic oxidase (11E,13Z-forming)
Comments: The enzyme, characterized from the plants Punica granatum (pomegranate) and Trichosanthes kirilowii (Mongolian snake-gourd), converts a single cis double bond at position 12 of linoleate incorporated into phosphatidylcholine into conjugated 11-trans and 13-cis double bonds. cf. EC 1.14.19.33, Δ12 acyl-lipid conjugase (11E,13E-forming).
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Hornung, E., Pernstich, C. and Feussner, I. Formation of conjugated Δ11Δ13-double bonds by Δ12-linoleic acid (1,4)-acyl-lipid-desaturase in pomegranate seeds. Eur. J. Biochem. 269 (2002) 4852-4859. [PMID: 12354116]
2. Iwabuchi, M., Kohno-Murase, J. and Imamura, J. Δ12-oleate desaturase-related enzymes associated with formation of conjugated trans-Δ11, cis-Δ13 double bonds. J. Biol. Chem. 278 (2003) 4603-4610. [PMID: 12464604]
Accepted name: sphingolipid 4-desaturase
Reaction: a dihydroceramide + 2 ferrocytochrome b5 + O2 + 2 H+ = a (4E)-sphing-4-enine ceramide + 2 ferricytochrome b5 + 2 H2O
Glossary: a dihydroceramide = an N-acylsphinganine
Other name(s): dehydroceramide desaturase
Systematic name: dihydroceramide,ferrocytochrome b5:oxygen oxidoreductase (4,5-dehydrogenating)
Comments: The enzyme, which has been characterized from plants, fungi, and mammals, generates a trans double bond at position 4 of sphinganine bases in sphingolipids [1]. The preferred substrate is dihydroceramide, but the enzyme is also active with dihydroglucosylceramide [2]. Unlike EC 1.14.19.29, sphingolipid 8-desaturase, this enzyme does not contain an integral cytochrome b5 domain [4] and requires an external cytochrome b5 [3]. The product serves as an important signalling molecules in mammals and is required for spermatide differentiation [5].
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Stoffel, W., Assmann, G. and Bister, K. Metabolism of sphingosine bases. XVII. Stereospecificities in the introduction of the 4t-double bond into sphinganine yielding 4t-sphingenine (sphingosine). Hoppe-Seylers Z. Physiol. Chem. 352 (1971) 1531-1544. [PMID: 5140816]
2. Michel, C., van Echten-Deckert, G., Rother, J., Sandhoff, K., Wang, E. and Merrill, A.H., Jr. Characterization of ceramide synthesis. A dihydroceramide desaturase introduces the 4,5-trans-double bond of sphingosine at the level of dihydroceramide. J. Biol. Chem. 272 (1997) 22432-22437. [PMID: 9312549]
3. Causeret, C., Geeraert, L., Van der Hoeven, G., Mannaerts, G.P. and Van Veldhoven, P.P. Further characterization of rat dihydroceramide desaturase: tissue distribution, subcellular localization, and substrate specificity. Lipids 35 (2000) 1117-1125. [PMID: 11104018]
4. Ternes, P., Franke, S., Zähringer, U., Sperling, P. and Heinz, E. Identification and characterization of a sphingolipid Δ4-desaturase family. J. Biol. Chem. 277 (2002) 25512-25518. [PMID: 11937514]
5. Michaelson, L.V., Zäuner, S., Markham, J.E., Haslam, R.P., Desikan, R., Mugford, S., Albrecht, S., Warnecke, D., Sperling, P., Heinz, E. and Napier, J.A. Functional characterization of a higher plant sphingolipid Δ4-desaturase: defining the role of sphingosine and sphingosine-1-phosphate in Arabidopsis. Plant Physiol. 149 (2009) 487-498. [PMID: 18978071]
Accepted name: sphingolipid 8-(E)-desaturase
Reaction: a (4E)-sphing-4-enine ceramide + 2 ferrocytochrome b5 + O2 + 2 H+ = a (4E,8E)-sphing-4,8-dienine ceramide + 2 ferricytochrome b5 + 2 H2O
Other name(s): 8-sphingolipid desaturase (ambiguous); 8 fatty acid desaturase (ambiguous); DELTA8-sphingolipid desaturase (ambiguous)
Systematic name: (4E)-sphing-4-enine ceramide,ferrocytochrome b5:oxygen oxidoreductase (8,9-trans dehydrogenating)
Comments: The enzyme, characterized from the yeasts Kluyveromyces lactis and Candida albicans [1] and from the diatom Thalassiosira pseudonana [2], introduces a trans double bond at the 8-position of sphingoid bases in sphingolipids. The enzyme determines the position of the double bond by its distance from the alcohol end of the sphingoid base, and contains a cytochrome b5 domain that acts as the direct electron donor to the active site of the desaturase [3]. The homologous enzymes from higher plants, EC 1.14.19.29, sphingolipid 8-(E/Z)-desaturase, act on phytosphinganine (4-hydroxysphinganine) and produces a mixture of trans and cis isomers.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Takakuwa, N., Kinoshita, M., Oda, Y. and Ohnishi, M. Isolation and characterization of the genes encoding Δ8-sphingolipid desaturase from Saccharomyces kluyveri and Kluyveromyces lactis. Curr. Microbiol. 45 (2002) 459-461. [PMID: 12402089]
2. Tonon, T., Sayanova, O., Michaelson, L.V., Qing, R., Harvey, D., Larson, T.R., Li, Y., Napier, J.A. and Graham, I.A. Fatty acid desaturases from the microalga Thalassiosira pseudonana. FEBS J. 272 (2005) 3401-3412. [PMID: 15978045]
3. Oura, T. and Kajiwara, S. Disruption of the sphingolipid Δ8-desaturase gene causes a delay in morphological changes in Candida albicans. Microbiology 154 (2008) 3795-3803. [PMID: 19047747]
Accepted name: sphingolipid 10-desaturase
Reaction: a (4E,8E)-sphinga-4,8-dienine ceramide + 2 ferrocytochrome b5 + O2 + 2 H+ = a (4E,8E,10E)-sphinga-4,8,10-trienine ceramide + 2 ferricytochrome b5 + 2 H2O
Other name(s): desA (gene name)
Systematic name: a (4E,8E)-sphinga-4,8-dienine ceramide,ferrocytochrome b5:oxygen oxidoreductase (10,11 trans-dehydrogenating)
Comments: The enzyme, characterized from the marine diatom Thalassiosira pseudonana, produces an all-trans product. Similar triunsaturated sphingoid bases are found in some marine invertebrates. The enzyme determines the position of the double bond by its distance from the alcohol end of the sphingoid base, and contains a cytochrome b5 domain that acts as the direct electron donor to the active site of the desaturase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Michaelson, L.V., Markham, J.E., Zäuner, S., Matsumoto, M., Chen, M., Cahoon, E.B. and Napier, J.A. Identification of a cytochrome b5-fusion desaturase responsible for the synthesis of triunsaturated sphingolipid long chain bases in the marine diatom Thalassiosira pseudonana. Phytochemistry 90 (2013) 50-55. [PMID: 23510654]
Accepted name: Δ7-sterol 5(6)-desaturase
Reaction: a Δ7-sterol + 2 ferrocytochrome b5 + O2 + 2 H+ = a Δ5,7-sterol + 2 ferricytochrome b5 + 2 H2O
For diagram of reaction click here.
Other name(s): lathosterol oxidase; Δ7-sterol Δ5-dehydrogenase; Δ7-sterol 5-desaturase; Δ7-sterol-C5(6)-desaturase; 5-DES; SC5DL (gene name); ERG3 (gene name)
Systematic name: Δ7-sterol,ferrocytochrome b5:oxygen oxidoreductase 5,6-dehydrogenating
Comments: This enzyme, found in eukaryotic organisms, catalyses the introduction of a double bond between the C5 and C6 carbons of the B ring of Δ7-sterols, to yield the corresponding Δ5,7-sterols. The enzymes from yeast, plants and vertebrates act on avenasterol, episterol, and lathosterol, respectively. The enzyme is located at the endoplasmic reticulum and is membrane bound.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Dempsey, M.E., Seaton, J.D., Schroepfer, G.J. and Trockman, R.W. The intermediary role of Δ5,7-cholestadien-3β-ol in cholesterol biosynthesis. J. Biol. Chem. 239 (1964) 1381-1387. [PMID: 14189869]
2. Honjo, K., Ishibashi, T. and Imai, Y. Partial purification and characterization of lathosterol 5-desaturase from rat liver microsomes. J. Biochem. 97 (1985) 955-959. [PMID: 4019441]
3. Arthington, B.A., Bennett, L.G., Skatrud, P.L., Guynn, C.J., Barbuch, R.J., Ulbright, C.E. and Bard, M. Cloning, disruption and sequence of the gene encoding yeast C-5 sterol desaturase. Gene 102 (1991) 39-44. [PMID: 1864507]
4. Taton, M. and Rahier, A. Plant sterol biosynthesis: identification and characterization of higher plant Δ7-sterol C5(6)-desaturase. Arch. Biochem. Biophys. 325 (1996) 279-288. [PMID: 8561508]
5. Nishino, H., Nakaya, J., Nishi, S., Kurosawa, T. and Ishibashi, T. Temperature-induced differential kinetic properties between an initial burst and the following steady state in membrane-bound enzymes: studies on lathosterol 5-desaturase. Arch. Biochem. Biophys. 339 (1997) 298-304. [PMID: 9056262]
6. Taton, M., Husselstein, T., Benveniste, P. and Rahier, A. Role of highly conserved residues in the reaction catalyzed by recombinant Δ7-sterol-C5(6)-desaturase studied by site-directed mutagenesis. Biochemistry 39 (2000) 701-711. [PMID: 10651635]
7. Poklepovich, T.J., Rinaldi, M.A., Tomazic, M.L., Favale, N.O., Turkewitz, A.P., Nudel, C.B. and Nusblat, A.D. The cytochrome b5 dependent C-5(6) sterol desaturase DES5A from the endoplasmic reticulum of Tetrahymena thermophila complements ergosterol biosynthesis mutants in Saccharomyces cerevisiae. Steroids 77 (2012) 1313-1320. [PMID: 22982564]
Accepted name: cholesterol 7-desaturase
Reaction: cholesterol + O2 + NAD(P)H + H+ = cholesta-5,7-dien-3β-ol + NAD(P)+ + 2 H2O
Other name(s): nvd (gene name); daf-36 (gene name)
Systematic name: cholesterol,NAD(P)H:oxygen oxidoreductase (7,8 dehydrogenating)
Comments: The enzyme, characterized from several organisms including the worm Caenorhabditis elegans, the fly Drosophila melanogaster, and the ciliate Tetrahymena thermophila, is a Rieske oxygenase. In insects it participates in the the biosythesis of ecdysteroid hormones. The electrons are transferred from NAD(P)H via an electron transfer chain likely to include ferredoxin reductase and ferredoxin. The enzyme differs from regular desaturases, such as EC 1.14.19.20, 7-sterol 5(6)-desaturase, which are cytochrome b5-dependent and contain the three His-boxes that are typical to most desaturases.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Yoshiyama-Yanagawa, T., Enya, S., Shimada-Niwa, Y., Yaguchi, S., Haramoto, Y., Matsuya, T., Shiomi, K., Sasakura, Y., Takahashi, S., Asashima, M., Kataoka, H. and Niwa, R. The conserved Rieske oxygenase DAF-36/Neverland is a novel cholesterol-metabolizing enzyme. J. Biol. Chem. 286 (2011) 25756-25762. [PMID: 21632547]
2. Wollam, J., Magomedova, L., Magner, D.B., Shen, Y., Rottiers, V., Motola, D.L., Mangelsdorf, D.J., Cummins, C.L. and Antebi, A. The Rieske oxygenase DAF-36 functions as a cholesterol 7-desaturase in steroidogenic pathways governing longevity. Aging Cell 10 (2011) 879-884. [PMID: 21749634]
3. Najle, S.R., Nusblat, A.D., Nudel, C.B. and Uttaro, A.D. The sterol-C7 desaturase from the ciliate Tetrahymena thermophila is a Rieske oxygenase, which is highly conserved in animals. Mol Biol Evol 30 (2013) 1630-1643. [PMID: 23603937]
4. Barry, S.M. and Challis, G.L. Mechanism and catalytic diversity of Rieske non-heme iron-dependent oxygenases. ACS Catal. 3 (2013) 2362-2370. [PMID: 24244885]
Accepted name: acyl-lipid ω-6 desaturase (cytochrome b5)
Reaction: an oleoyl-[glycerolipid] + 2 ferrocytochrome b5 + O2 + 2 H+ = a linoleoyl-[glycerolipid] + 2 ferricytochrome b5 + 2 H2O
Other name(s): oleate desaturase (ambiguous); linoleate synthase (ambiguous); oleoyl-CoA desaturase (incorrect); oleoylphosphatidylcholine desaturase (ambiguous); phosphatidylcholine desaturase (ambiguous); n-6 desaturase (ambiguous); FAD2 (gene name)
Systematic name: 1-acyl-2-oleoyl-sn-glycero-3-phosphocholine,ferrocytochrome-b5:oxygen oxidoreductase (12,13 cis-dehydrogenating)
Comments: This microsomal enzyme introduces a cis double bond in fatty acids attached to lipid molecules at a location 6 carbons away from the methyl end of the fatty acid. The distance from the carboxylic acid end of the molecule does not affect the location of the new double bond. The most common substrates are oleoyl groups attached to either the sn-1 or sn-2 position of the glycerol backbone in phosphatidylcholine. cf. EC 1.14.19.23, acyl-lipid ω-6 desaturase (ferredoxin).
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Pugh, E.L. and Kates, M. Characterization of a membrane-bound phospholipid desaturase system of Candida lipolytica. Biochim. Biophys. Acta 380 (1975) 442-453. [PMID: 166662]
2. Slack, C.R., Roughan, P.G. and Browse, J. Evidence for an oleoyl phosphatidylcholine desaturase in microsomal preparations from cotyledons of safflower (Carthamus tinctorius) seed. Biochem. J. 179 (1979) 649-656. [PMID: 475773]
3. Stymne, S. and Appelqvist, L.-A. The biosynthesis of linoleate from oleoyl-CoA via oleoyl-phosphatidylcholine in microsomes of developing safflower seeds. Eur. J. Biochem. 90 (1978) 223-229. [PMID: 710426]
4. Smith, M.A., Cross, A.R., Jones, O.T., Griffiths, W.T., Stymne, S. and Stobart, K. Electron-transport components of the 1-acyl-2-oleoyl-sn-glycero-3-phosphocholine Δ12-desaturase (Δ12-desaturase) in microsomal preparations from developing safflower (Carthamus tinctorius L.) cotyledons. Biochem. J. 272 (1990) 23-29. [PMID: 2264826]
5. Kearns, E.V., Hugly, S. and Somerville, C.R. The role of cytochrome b5 in Δ12 desaturation of oleic acid by microsomes of safflower (Carthamus tinctorius L.). Arch. Biochem. Biophys. 284 (1991) 431-436. [PMID: 1989527]
6. Miquel, M. and Browse, J. Arabidopsis mutants deficient in polyunsaturated fatty acid synthesis. Biochemical and genetic characterization of a plant oleoyl-phosphatidylcholine desaturase. J. Biol. Chem. 267 (1992) 1502-1509. [PMID: 1730697]
Accepted name: acyl-lipid (n+3)-(Z)-desaturase (ferredoxin)
Reaction: an oleoyl-[glycerolipid] + 2 reduced ferredoxin [iron-sulfur] cluster + O2 + 2 H+ = a linoleoyl-[glycerolipid] + 2 oxidized ferredoxin [iron-sulfur] cluster + 2 H2O
Other name(s): acyl-lipid ω6-desaturase (ferredoxin); oleate desaturase (ambiguous); linoleate synthase (ambiguous); oleoyl-CoA desaturase (ambiguous); oleoylphosphatidylcholine desaturase (ambiguous); phosphatidylcholine desaturase (ambiguous); FAD6 (gene name)
Systematic name: oleoyl-[glycerolipid],ferredoxin:oxygen oxidoreductase (12,13 cis-dehydrogenating)
Comments: This plastidial enzyme is able to insert a cis double bond in monounsaturated fatty acids incorporated into glycerolipids. The enzyme introduces the new bond at a position 3 carbons away from the existing double bond, towards the methyl end of the fatty acid. The native substrates are oleoyl (18:1 Δ9) and (Z)-hexadec-7-enoyl (16:1 Δ7) groups attached to either position of the glycerol backbone in glycerolipids, resulting in the introduction of the second double bond at positions 12 and 10, respectively This prompted the suggestion that this is an ω6 desaturase. However, when acting on palmitoleoyl groups(16:1 Δ9), the enzyme introduces the second double bond at position 12 (ω4), indicating it is an (n+3) desaturase [3]. cf. EC 1.14.19.34, acyl-lipid (9+3)-(E)-desaturase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Schmidt, H. and Heinz, E. Desaturation of oleoyl groups in envelope membranes from spinach chloroplasts. Proc. Natl. Acad. Sci. USA 87 (1990) 9477-9480. [PMID: 11607123]
2. Schmidt, H. and Heinz, E. Involvement of ferredoxin in desaturation of lipid-bound oleate in chloroplasts. Plant Physiol. 94 (1990) 214-220. [PMID: 16667689]
3. Hitz, W.D., Carlson, T.J., Booth, J.R., Jr., Kinney, A.J., Stecca, K.L. and Yadav, N.S. Cloning of a higher-plant plastid ω-6 fatty acid desaturase cDNA and its expression in a cyanobacterium. Plant Physiol. 105 (1994) 635-641. [PMID: 8066133]
4. Falcone, D.L., Gibson, S., Lemieux, B. and Somerville, C. Identification of a gene that complements an Arabidopsis mutant deficient in chloroplast ω 6 desaturase activity. Plant Physiol. 106 (1994) 1453-1459. [PMID: 7846158]
5. Schmidt, H., Dresselhaus, T., Buck, F. and Heinz, E. Purification and PCR-based cDNA cloning of a plastidial n-6 desaturase. Plant Mol. Biol. 26 (1994) 631-642. [PMID: 7948918]
Accepted name: acyl-CoA 11-(E)-desaturase
Reaction: an acyl-CoA + 2 ferrocytochrome b5 + O2 + 2 H+ = an (11E)-enoyl-CoA + 2 ferricytochrome b5 + 2 H2O
Systematic name: acyl-CoA,ferrocytochrome b5:oxygen oxidoreductase (11,12 trans-dehydrogenating)
Comments: Involved in sex pheromone synthesis in the Lepidoptera (moths). The enzyme from the moth Spodoptera littoralis prefers 13:0 and 14:0 substrates. The product is formed by the stereospecific removal of the pro-R H at C-11 and the pro-S H at C-12. cf. EC 1.14.19.5, acyl-CoA 11-(Z)-desaturase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Foster, S. P. and Roelofs, W. L. Biosynthesis of a monoene and a conjugated diene sex pheromone component of the lightbrown apple moth by 11 desaturation. Experientia 46 (1990) 269-273.
2. Martinez, T., Fabrias, G. and Camps, F. Sex pheromone biosynthetic pathway in Spodoptera littoralis and its activation by a neurohormone. J. Biol. Chem. 265 (1990) 1381-1387. [PMID: 2295634]
3. Navarro, I., Font, I., Fabrias, G. and Camps, F. Stereospecificity of the (E)- and (Z)-11 myristoyl desaturases in the biosynthesis of Spodoptera littoralis sex pheromone. J. Am. Chem. Soc. 119 (1997) 11335-11336.
4. Pinilla, A., Camps, F. and Fabrias, G. Cryptoregiochemistry of the Δ11-myristoyl-CoA desaturase involved in the biosynthesis of Spodoptera littoralis sex pheromone. Biochemistry 38 (1999) 15272-15277. [PMID: 10563812]
Accepted name: acyl-lipid ω-3 desaturase (cytochrome b5)
Reaction: a linoleoyl-[glycerolipid] + 2 ferrocytochrome b5 + O2 + 2 H+ = an α-linolenoyl-[glycerolipid] + 2 ferricytochrome b5 + 2 H2O
Glossary: linoleoyl-[glycerolipid] = (9Z,12Z)-octadeca-9,12-dienoyl-[glycerolipid]
α-linolenoyl-[glycerolipid] = (9Z,12Z,15Z)-octadeca-9,12,15-trienoyl-[glycerolipid]
Other name(s): FAD3
Systematic name: (9Z,12Z)-octadeca-9,12-dienoyl-[glycerolipid],ferrocytochrome b5:oxygen oxidoreductase (15,16 cis-dehydrogenating)
Comments: This microsomal enzyme introduces a cis double bond three carbons away from the methyl end of a fatty acid incorporated into a glycerolipid. The distance from the carboxylic acid end of the molecule does not have an effect. The plant enzyme acts on carbon 15 of linoleoyl groups incorporated into both the sn-1 and sn-2 positions of the glycerol backbone of phosphatidylcholine and other phospholipids, converting them into α-linolenoyl groups. The enzyme from the fungus Mortierella alpina acts on γ-linolenoyl and arachidonoyl groups, converting them into stearidonoyl and icosapentaenoyl groups, respectively [3]. cf. EC 1.14.19.35, acyl-lipid ω-3 desaturase (ferredoxin).
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Browse, J., McConn, M., James, D., Jr. and Miquel, M. Mutants of Arabidopsis deficient in the synthesis of α-linolenate. Biochemical and genetic characterization of the endoplasmic reticulum linoleoyl desaturase. J. Biol. Chem. 268 (1993) 16345-16351. [PMID: 8102138]
2. Arondel, V., Lemieux, B., Hwang, I., Gibson, S., Goodman, H.M. and Somerville, C.R. Map-based cloning of a gene controlling ω-3 fatty acid desaturation in Arabidopsis. Science 258 (1992) 1353-1355. [PMID: 1455229]
3. Sakuradani, E., Abe, T., Iguchi, K. and Shimizu, S. A novel fungal ω3-desaturase with wide substrate specificity from arachidonic acid-producing Mortierella alpina 1S-4. Appl. Microbiol. Biotechnol. 66 (2005) 648-654. [PMID: 15538555]
Accepted name: acyl-[acyl-carrier-protein] 6-desaturase
Reaction: palmitoyl-[acyl-carrier protein] + 2 reduced ferredoxin [iron-sulfur] cluster + O2 + 2 H+ = (6Z)-hexadec-6-enoyl-[acyl-carrier protein] + 2 oxidized ferredoxin [iron-sulfur] cluster + 2 H2O
Glossary: (6Z)-hexadec-6-enoyl-[acyl-carrier protein] = Δ6-hexadecenoyl-[acyl-carrier protein] = sapienoyl-[acyl-carrier-protein]
an [acyl-carrier protein] = ACP = [acp]
Other name(s): DELTA6 palmitoyl-ACP desaturase; DELTA6 16:0-ACP desaturase
Systematic name: palmitoyl-[acyl-carrier protein],reduced ferredoxin:oxygen oxidoreductase (6,7 cis-dehydrogenating)
Comments: The enzyme, characterized from the endosperm of the plant Thunbergia alata (black-eyed Susan vine), introduces a cis double bond at carbon 6 of several saturated acyl-[acp]s. It is most active with palmitoyl-[acp] (16:0), but can also act on myristoyl-[acp] (14:0) and stearoyl-[acp] (18:0). The position of the double bond is determined by its distance from the carboxyl end of the fatty acid.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:
References:
1. Cahoon, E.B., Cranmer, A.M., Shanklin, J. and Ohlrogge, J.B. Δ6 Hexadecenoic acid is synthesized by the activity of a soluble Δ6 palmitoyl-acyl carrier protein desaturase in Thunbergia alata endosperm. J. Biol. Chem. 269 (1994) 27519-27526. [PMID: 7961667]
2. Cahoon, E.B., Lindqvist, Y., Schneider, G. and Shanklin, J. Redesign of soluble fatty acid desaturases from plants for altered substrate specificity and double bond position. Proc. Natl. Acad. Sci. USA 94 (1997) 4872-4877. [PMID: 9144157]
Accepted name: sn-2 palmitoyl-lipid 9-desaturase
Reaction: a 1-acyl-2-palmitoyl-[glycerolipid] + 2 reduced ferredoxin [iron-sulfur] cluster + O2 + 2 H+ = a 1-acyl-2-palmitoleoyl-[glycerolipid] + 2 oxidized ferredoxin [iron-sulfur] cluster + 2 H2O
Other name(s): DesC2
Systematic name: 1-acyl-2-palmitoyl-[glycerolipid],ferredoxin:oxygen oxidoreductase (9,10 cis-dehydrogenating)
Comments: The enzyme, characterized from the cyanobacterium Nostoc sp. 36, introduces a cis double bond at carbon 9 of palmitoyl groups (16:0) attached to the sn-2 position of glycerolipids.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Chintalapati, S., Prakash, J.S., Gupta, P., Ohtani, S., Suzuki, I., Sakamoto, T., Murata, N. and Shivaji, S. A novel Δ9 acyl-lipid desaturase, DesC2, from cyanobacteria acts on fatty acids esterified to the sn-2 position of glycerolipids. Biochem. J. 398 (2006) 207-214. [PMID: 16689682]
Accepted name: sn-1 stearoyl-lipid 9-desaturase
Reaction: a 1-stearoyl-2-acyl-[glycerolipid] + 2 reduced ferredoxin [iron-sulfur] cluster + O2 + 2 H+ = a 1-oleoyl-2-acyl-[glycerolipid] + 2 oxidized ferredoxin [iron-sulfur] cluster + 2 H2O
Other name(s): desC (gene name)
Systematic name: 1-stearoyl-2-acyl-[glycerolipid],ferredoxin:oxygen oxidoreductase (9,10 cis-dehydrogenating)
Comments: The enzyme, characterized from cyanobacteria, introduces a cis double bond at carbon 9 of stearoyl groups (18:0) attached to the sn-1 position of glycerolipids. The enzyme is nonspecific with respect to the polar head group of the glycerolipid.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Wada, H., Schmidt, H., Heinz, E. and Murata, N. In vitro ferredoxin-dependent desaturation of fatty acids in cyanobacterial thylakoid membranes. J. Bacteriol. 175 (1993) 544-547. [PMID: 8419301]
2. Higashi, S. and Murata, N. An in vivo study of substrate specificities of acyl-lipid desaturases and acyltransferases in lipid synthesis in Synechocystis PCC6803. Plant Physiol. 102 (1993) 1275-1278. [PMID: 12231903]
3. Sakamoto, T., Wada, H., Nishida, I., Ohmori, M. and Murata, N. Δ9 Acyl-lipid desaturases of cyanobacteria. Molecular cloning and substrate specificities in terms of fatty acids, sn-positions, and polar head groups. J. Biol. Chem. 269 (1994) 25576-25580. [PMID: 7929259]
Accepted name: sphingolipid 8-(E/Z)-desaturase
Reaction: (1) a (4R)-4-hydroxysphinganine ceramide + 2 ferrocytochrome b5 + O2 + 2 H+ = a (4R,8E)-4-hydroxysphing-8-enine ceramide + 2 ferricytochrome b5 + 2 H2O
(2) a (4R)-4-hydroxysphinganine ceramide + 2 ferrocytochrome b5 + O2 + 2 H+ = a (4R,8Z)-4-hydroxysphing-8-enine ceramide + 2 ferricytochrome b5 + 2 H2O
Glossary: a (4R)-4-hydroxysphinganine-ceramide = a phytoceramide
(4R)-4-hydroxysphinganine = phytosphinganine
Other name(s): 8-sphingolipid desaturase (ambiguous); 8 fatty acid desaturase (ambiguous); DELTA8-sphingolipid desaturase (ambiguous)
Systematic name: (4R)-4-hydroxysphinganine ceramide,ferrocytochrome b5:oxygen oxidoreductase (8,9 cis/trans-dehydrogenating)
Comments: The enzymes from higher plants convert sphinganine, 4E-sphing-4-enine and phytosphinganine into E/Z-mixtures of Δ8-desaturated products displaying different proportions of geometrical isomers depending on plant species. The nature of the actual desaturase substrate has not yet been studied experimentally. The enzymes contain an N-terminal cytochrome b5 domain that acts as the direct electron donor to the active site of the desaturase [1]. The homologous enzymes from some yeasts and diatoms, EC 1.14.19.18, sphingolipid 8-(E)-desaturase, act on sphing-4-enine ceramides and produce only the trans isomer.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Sperling, P., Zähringer, U. and Heinz, E. A sphingolipid desaturase from higher plants. Identification of a new cytochrome b5 fusion protein. J. Biol. Chem. 273 (1998) 28590-28596. [PMID: 9786850]
2. Sperling, P., Blume, A., Zähringer, U., and Heinz, E. Further characterization of Δ8-sphingolipid desaturases from higher plants. Biochem Soc Trans. 28 (2000) 638-641.
3. Sperling, P., Libisch, B., Zähringer, U., Napier, J.A. and Heinz, E. Functional identification of a Δ8-sphingolipid desaturase from Borago officinalis. Arch. Biochem. Biophys. 388 (2001) 293-298. [PMID: 11368168]
4. Beckmann, C., Rattke, J., Oldham, N.J., Sperling, P., Heinz, E. and Boland, W. Characterization of a Δ8-sphingolipid desaturase from higher plants: a stereochemical and mechanistic study on the origin of E,Z isomers. Angew. Chem. Int. Ed. Engl. 41 (2002) 2298-2300. [PMID: 12203571]
5. Ryan, P.R., Liu, Q., Sperling, P., Dong, B., Franke, S. and Delhaize, E. A higher plant Δ8 sphingolipid desaturase with a preference for (Z)-isomer formation confers aluminum tolerance to yeast and plants. Plant Physiol. 144 (2007) 1968-1977. [PMID: 17600137]
6. Chen, M., Markham, J.E. and Cahoon, E.B. Sphingolipid Δ8 unsaturation is important for glucosylceramide biosynthesis and low-temperature performance in Arabidopsis. Plant J. 69 (2012) 769-781. [PMID: 22023480]
Accepted name: acyl-lipid (8-3)-desaturase
Reaction: (1) an (8Z,11Z,14Z)-icosa-8,11,14-trienoyl-[glycerolipid] + 2 ferrocytochrome b5 + O2 + 2 H+ = a (5Z,8Z,11Z,14Z)-icosatetra-5,8,11,14-tetraenoyl-[glycerolipid] + 2 ferricytochrome b5 + 2 H2O
(2) an (8Z,11Z,14Z,17Z)-icosa-8,11,14,17-tetraenoyl-[glycerolipid] + 2 ferrocytochrome b5 + O2 + 2 H+ = a (5Z,8Z,11Z,14Z,17Z)-icosa-5,8,11,14,17-pentaenoyl-[glycerolipid] + 2 ferricytochrome b5 + 2 H2O
Glossary: (8Z,11Z,14Z)-icosa-8,11,14-trienoate = di-homo-γ-linolenate
(5Z,8Z,11Z,14Z)-icosa-8,11,14-trienoate = arachidonate
Other name(s): acyl-lipid 5-desaturase; Δ5-fatty-acid desaturase; DES5 (gene name); D5des (gene name); FADS1
Systematic name: Δ8 acyl-lipid,ferrocytochrome b5:oxygen oxidoreductase (5,6 cis-dehydrogenating)
Comments: The enzyme, which has been characterized from multiple organisms including the moss Physcomitrella patens, the marine microalga Rebecca salina, and the filamentous fungus Mortierella alpina, introduces a cis double bond at the 5-position in 20-carbon polyunsaturated fatty acids incorporated in a glycerolipid that contain a Δ8 double bond. The enzyme contains a cytochrome b5 domain that acts as the direct electron donor to the active site of the desaturase, and does not require an external cytochrome.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Michaelson, L.V., Lazarus, C.M., Griffiths, G., Napier, J.A. and Stobart, A.K. Isolation of a Δ5-fatty acid desaturase gene from Mortierella alpina. J. Biol. Chem. 273 (1998) 19055-19059. [PMID: 9668087]
2. Kaewsuwan, S., Cahoon, E.B., Perroud, P.F., Wiwat, C., Panvisavas, N., Quatrano, R.S., Cove, D.J. and Bunyapraphatsara, N. Identification and functional characterization of the moss Physcomitrella patens Δ5-desaturase gene involved in arachidonic and eicosapentaenoic acid biosynthesis. J. Biol. Chem. 281 (2006) 21988-21997. [PMID: 16728405]
3. Zhou, X.R., Robert, S.S., Petrie, J.R., Frampton, D.M., Mansour, M.P., Blackburn, S.I., Nichols, P.D., Green, A.G. and Singh, S.P. Isolation and characterization of genes from the marine microalga Pavlova salina encoding three front-end desaturases involved in docosahexaenoic acid biosynthesis. Phytochemistry 68 (2007) 785-796. [PMID: 17291553]
Accepted name: acyl-lipid (7-3)-desaturase
Reaction: (1) a (7Z,10Z,13Z,16Z,19Z)-docosa-7,10,13,16,19-pentaenoyl-[glycerolipid] + 2 ferrocytochrome b5 + O2 + 2 H+ = a (4Z,7Z,10Z,13Z,16Z,19Z)-docosa-4,7,10,13,16,19-hexaenoyl-[glycerolipid] + 2 ferricytochrome b5 + 2 H2O
(2) a (7Z,10Z,13Z,16Z)-docosa-7,10,13,16-tetraenoyl-[glycerolipid] + 2 ferrocytochrome b5 + O2 + 2 H+ = a (4Z,7Z,10Z,13Z,16Z)-docosa-4,7,10,13,16-pentaenoyl-[glycerolipid] + 2 ferricytochrome b5 + 2 H2O
Glossary: (7Z,10Z,13Z,16Z)-docosa-7,10,13,16-tetraenoate = adrenate
Other name(s): D4Des (gene name); des1 (gene name); CrΔ4FAD (gene name); acyl-lipid 4-desaturase
Systematic name: Δ7 acyl-lipid,ferrocytochrome b5:oxygen oxidoreductase (4,5 cis-dehydrogenating)
Comments: The enzymes from several algae introduce a cis double bond at the 4-position in 22-carbon polyunsaturated fatty acids that contain a Δ7 double bond. The enzyme from the fresh water alga Chlamydomonas reinhardtii acts on the 16 carbon fatty acid (7Z,10Z,13Z)-hexadeca-7,10,13-trienoate [5]. The enzyme contains an N-terminal cytochrome b5 domain that acts as the direct electron donor to the active site of the desaturase, and does not require an external cytochrome.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Qiu, X., Hong, H. and MacKenzie, S.L. Identification of a Δ4 fatty acid desaturase from Thraustochytrium sp. involved in the biosynthesis of docosahexanoic acid by heterologous expression in Saccharomyces cerevisiae and Brassica juncea. J. Biol. Chem. 276 (2001) 31561-31566. [PMID: 11397798]
2. Tonon, T., Harvey, D., Larson, T.R. and Graham, I.A. Identification of a very long chain polyunsaturated fatty acid Δ4-desaturase from the microalga Pavlova lutheri. FEBS Lett. 553 (2003) 440-444. [PMID: 14572666]
3. Meyer, A., Cirpus, P., Ott, C., Schlecker, R., Zähringer, U. and Heinz, E. Biosynthesis of docosahexaenoic acid in Euglena gracilis: biochemical and molecular evidence for the involvement of a Δ4-fatty acyl group desaturase. Biochemistry 42 (2003) 9779-9788. [PMID: 12911321]
4. Zhou, X.R., Robert, S.S., Petrie, J.R., Frampton, D.M., Mansour, M.P., Blackburn, S.I., Nichols, P.D., Green, A.G. and Singh, S.P. Isolation and characterization of genes from the marine microalga Pavlova salina encoding three front-end desaturases involved in docosahexaenoic acid biosynthesis. Phytochemistry 68 (2007) 785-796. [PMID: 17291553]
5. Zäuner, S., Jochum, W., Bigorowski, T. and Benning, C. A cytochrome b5-containing plastid-located fatty acid desaturase from Chlamydomonas reinhardtii. Eukaryot Cell 11 (2012) 856-863. [PMID: 22562471]
Accepted name: palmitoyl-CoA 14-(E/Z)-desaturase
Reaction: (1) palmitoyl-CoA + 2 ferrocytochrome b5 + O2 + 2 H+ = (14E)-hexadec-14-enoyl-CoA + 2 ferricytochrome b5 + 2 H2O
(2) palmitoyl-CoA + 2 ferrocytochrome b5 + O2 + 2 H+ = (14Z)-hexadec-14-enoyl-CoA + 2 ferricytochrome b5 + 2 H2O
Systematic name: palmitoyl-CoA,ferrocytochrome b5:oxygen oxidoreductase (14,15 cis/trans-dehydrogenating)
Comments: The enzyme, found in the moth Ostrinia furnacalis (Asian corn borer), produces a mixture of (E)- and (Z)- isomers. The products are subsequently truncated by partial β-oxidation to a blend of 12(E/Z)-tetradec-12-enoyl-CoA, which are converted to the species-specific sex pheromones (E)- and (Z)-tetradec-12-enoyl acetates.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Roelofs, W.L., Liu, W., Hao, G., Jiao, H., Rooney, A.P. and Linn, C.E., Jr. Evolution of moth sex pheromones via ancestral genes. Proc. Natl. Acad. Sci. USA 99 (2002) 13621-13626. [PMID: 12237399]
2. Xue, B., Rooney, A.P., Kajikawa, M., Okada, N. and Roelofs, W.L. Novel sex pheromone desaturases in the genomes of corn borers generated through gene duplication and retroposon fusion. Proc. Natl. Acad. Sci. USA 104 (2007) 4467-4472. [PMID: 17360547]
3. Sakai, R., Fukuzawa, M., Nakano, R., Tatsuki, S. and Ishikawa, Y. Alternative suppression of transcription from two desaturase genes is the key for species-specific sex pheromone biosynthesis in two Ostrinia moths. Insect Biochem. Mol. Biol. 39 (2009) 62-67. [PMID: 18992816]
Accepted name: Δ12 acyl-lipid conjugase (11E,13E-forming)
Reaction: (1) a linoleoyl-[glycerolipid] + 2 ferrocytochrome b5 + O2 + 2 H+ = an α-eleostearoyl-[glycerolipid] + 2 ferricytochrome b5 + 2 H2O
(2) a γ-linolenoyl-[glycerolipid] + 2 ferrocytochrome b5 + O2 + 2 H+ = an α-parinaroyl-[glycerolipid] + 2 ferricytochrome b5 + 2 H2O
Glossary: α-eleostearate = (9Z,11E,13E)-octadeca-9,11,13-trienoate
α-parinarate = (9Z,11E,13E,15Z)-octadeca-9,11,13,15-tetraenoate
γ-linolenic acid = (6Z,9Z,12Z)-octadeca-6,9,12-trienoic acid
linoleic acid = (9Z,12Z)-octadeca-9,12-dienoic acid
Other name(s): fatty acid Δ12-conjugase (ambiguous); FADX (gene name)
Systematic name: Δ12 acyl-lipid,ferrocytochrome-b5:oxygen 11,14 allylic oxidase (11E,13E-forming)
Comments: The enzyme, characterized from the plants Impatiens balsamina, Momordica charantia (bitter gourd) and Vernicia fordii (tung tree), converts a single cis double bond at carbon 12 to two conjugated trans bonds at positions 11 and 13. The enzyme from Vernicia fordii can also act as a 12(E) desaturase when acting on the monounsaturated fatty acids oleate and palmitoleate. cf. EC 1.14.19.16, linoleoyl-lipid Δ12 conjugase (11E,13Z-forming).
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Cahoon, E.B., Carlson, T.J., Ripp, K.G., Schweiger, B.J., Cook, G.A., Hall, S.E. and Kinney, A.J. Biosynthetic origin of conjugated double bonds: production of fatty acid components of high-value drying oils in transgenic soybean embryos. Proc. Natl. Acad. Sci. USA 96 (1999) 12935-12940. [PMID: 10536026]
2. Dyer, J.M., Chapital, D.C., Kuan, J.C., Mullen, R.T., Turner, C., McKeon, T.A. and Pepperman, A.B. Molecular analysis of a bifunctional fatty acid conjugase/desaturase from tung. Implications for the evolution of plant fatty acid diversity. Plant Physiol. 130 (2002) 2027-2038. [PMID: 12481086]
Accepted name: acyl-lipid (9+3)-(E)-desaturase
Reaction: (1) an oleoyl-[glycerolipid] + 2 ferrocytochrome b5 + O2 + 2 H+ = a (9Z,12E)-octadeca-9,12-dienoyl-[glycerolipid] + 2 ferricytochrome b5 + 2 H2O
(2) a palmitoleoyl-[glycerolipid] + 2 ferrocytochrome b5 + O2 + 2 H+ = a (9Z,12E)-hexadeca-9,12-dienoyl-[glycerolipid] + 2 ferricytochrome b5 + 2 H2O
Other name(s): acyl-lipid 12-(E)-desaturase; DsFAD2-1; FADX
Systematic name: Δ9 acyl-lipid,ferrocytochrome b5:oxygen oxidoreductase (12,13 trans-dehydrogenating)
Comments: The enzymes from the plants Dimorphotheca sinuata (African daisy) and Vernicia fordii (tung oil tree) insert a trans double bond in position C-12 of oleate and palmitoleate incorporated into glycerolipids. The enzyme introduces the new double bond at a position three carbons away from an existing double bond at position 9, towards the methyl end of the fatty acid. The enzyme from tung oil tree also possesses the activity of EC 1.14.19.33, Δ12 acyl-lipid conjugase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Dyer, J.M., Chapital, D.C., Kuan, J.C., Mullen, R.T., Turner, C., McKeon, T.A. and Pepperman, A.B. Molecular analysis of a bifunctional fatty acid conjugase/desaturase from tung. Implications for the evolution of plant fatty acid diversity. Plant Physiol. 130 (2002) 2027-2038. [PMID: 12481086]
2. Cahoon, E.B. and Kinney, A.J. Dimorphecolic acid is synthesized by the coordinate activities of two divergent Δ12-oleic acid desaturases. J. Biol. Chem. 279 (2004) 12495-12502. [PMID: 14718523]
Accepted name: sn-2 acyl-lipid ω-3 desaturase (ferredoxin)
Reaction: (1) a (7Z,10Z)-hexadeca-7,10-dienoyl-[glycerolipid] + 2 reduced ferredoxin [iron-sulfur] cluster + O2 + 2 H+ = a (7Z,10Z,13Z)-hexadeca-7,10,13-trienoyl-[glycerolipid] + 2 oxidized ferredoxin [iron-sulfur] cluster + 2 H2O
(2) a linoleoyl-[glycerolipid] + 2 reduced ferredoxin [iron-sulfur] cluster + O2 + 2 H+ = an α-linolenoyl-[glycerolipid] + 2 oxidized ferredoxin [iron-sulfur] cluster + 2 H2O
Glossary: (9Z,12Z)-octadeca-9,12-dienoyl-[glycerolipid] = linoleoyl-[glycerolipid]
(9Z,12Z,15Z)-octadeca-9,12,15-trienoyl-[glycerolipid] = α-linolenoyl-[glycerolipid]
Other name(s): FAD7; FAD8
Systematic name: (7Z,10Z)-hexadeca-7,10-dienoyl-[glycerolipid],ferredoxin:oxygen oxidoreductase (13,14 cis-dehydrogenating)
Comments: This plastidial enzyme desaturates 16:2 fatty acids attached to the sn-2 position of glycerolipids to 16:3 fatty acids, and converts18:2 to 18:3 in both the sn-1 and sn-2 positions. It acts on all 16:2- or 18:2-containing chloroplast membrane lipids, including phosphatidylglycerol, monogalactosyldiacylglycerol, digalactosyldiaclyglycerol, and sulfoquinovosyldiacylglycerol. The enzyme introduces a cis double bond at a location 3 carbons away from the methyl end of the fatty acid. The distance from the carboxylic acid end of the molecule does not affect the location of the new double bond. cf. EC 1.14.19.25, acyl-lipid ω-3 desaturase (cytochrome b5) and EC 1.14.19.36, sn-1 acyl-lipid ω-3 desaturase (ferredoxin).
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Iba, K., Gibson, S., Nishiuchi, T., Fuse, T., Nishimura, M., Arondel, V., Hugly, S. and Somerville, C. A gene encoding a chloroplast ω-3 fatty acid desaturase complements alterations in fatty acid desaturation and chloroplast copy number of the fad7 mutant of Arabidopsis thaliana. J. Biol. Chem. 268 (1993) 24099-24105. [PMID: 8226956]
2. McConn, M., Hugly, S., Browse, J. and Somerville, C. A mutation at the fad8 locus of Arabidopsis identifies a second chloroplast ω-3 desaturase. Plant Physiol. 106 (1994) 1609-1614. [PMID: 12232435]
3. Venegas-Caleron, M., Muro-Pastor, A.M., Garces, R. and Martinez-Force, E. Functional characterization of a plastidial ω-3 desaturase from sunflower (Helianthus annuus) in cyanobacteria. Plant Physiol. Biochem. 44 (2006) 517-525. [PMID: 17064923]
Accepted name: sn-1 acyl-lipid ω-3 desaturase (ferredoxin)
Reaction: (1) a 1-γ-linolenoyl-2-acyl-[glycerolipid] + 2 reduced ferredoxin [iron-sulfur] cluster + O2 + 2 H+ = a 1-stearidonoyl-2-acyl-[glycerolipid] + 2 oxidized ferredoxin [iron-sulfur] cluster + 2 H2O
(2) a 1-linoleoyl-2-acyl-[glycerolipid] + 2 reduced ferredoxin [iron-sulfur] cluster + O2 + 2 H+ = a 1-α-linolenoyl-2-acyl-[glycerolipid] + 2 oxidized ferredoxin [iron-sulfur] cluster + 2 H2O
Glossary: stearidonic acid = (6Z,9Z,12Z,15Z)-octadeca-6,9,12,15-tetraenoic acid
Other name(s): desB (gene name)
Systematic name: 1-γ-linolenoyl-2-acyl-[glycerolipid],ferredoxin:oxygen oxidoreductase (15,16 cis-dehydrogenating)
Comments: The enzyme, characterized from cyanobacteria, introduces a cis double bond at carbon 15 of linoleoyl and γ-linolenoyl groups attached to the sn-1 position of glycerolipids. The enzyme is an ω desaturase, and determines the location of the double bond by counting three carbons from the methyl end of the fatty acid. It is nonspecific with respect to the polar head group of the glycerolipid. cf. EC 1.14.19.35, sn-2 acyl-lipid ω-3 desaturase (ferredoxin).
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Sakamoto, T., Los, D.A., Higashi, S., Wada, H., Nishida, I., Ohmori, M. and Murata, N. Cloning of ω3 desaturase from cyanobacteria and its use in altering the degree of membrane-lipid unsaturation. Plant Mol. Biol. 26 (1994) 249-263. [PMID: 7524725]
Accepted name: acyl-CoA 5-desaturase
Reaction: (1) (11Z,14Z)-icosa-11,14-dienoyl-CoA + reduced acceptor + O2 = (5Z,11Z,14Z)-icosa-5,11,14-trienoyl-CoA + acceptor + 2 H2O
(2) (11Z,14Z,17Z)-icosa-11,14,17-trienoyl-CoA + reduced acceptor + O2 = (5Z,11Z,14Z,17Z)-icosa-5,11,14,17-tetraenoyl-CoA + acceptor + 2 H2O
Glossary: (5Z,11Z,14Z)-icosa-5,11,14-trienoate = sciadonate
(5Z,11Z,14Z,17Z)-icosa-5,11,14,17-tetraenoate = juniperonate
Other name(s): acyl-CoA 5-desaturase (non-methylene-interrupted)
Systematic name: acyl-CoA,acceptor:oxygen oxidoreductase (5,6 cis-dehydrogenating)
Comments: The enzyme, characterized from the plant Anemone leveillei, introduces a cis double bond at carbon 5 of acyl-CoAs that do not contain a double bond at position 8. In vivo it forms non-methylene-interrupted polyunsaturated fatty acids such as sciadonate and juniperonate. When expressed in Arabidopsis thaliana the enzyme could also act on unsaturated substrates such as palmitoyl-CoA. cf. EC 1.14.19.44, acyl-CoA (8-3)-desaturase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Sayanova, O., Haslam, R., Venegas Caleron, M. and Napier, J.A. Cloning and characterization of unusual fatty acid desaturases from Anemone leveillei: identification of an acyl-coenzyme A C20 Δ5-desaturase responsible for the synthesis of sciadonic acid. Plant Physiol. 144 (2007) 455-467. [PMID: 17384161]
Accepted name: acyl-lipid Δ6-acetylenase
Reaction: (1) a γ-linolenoyl-[glycerolipid] + 2 ferrocytochrome b5 + O2 + 2 H+ = a (9Z,12Z)-octadeca-9,12-dien-6-ynoyl-[glycerolipid] + 2 ferricytochrome b5 + 2 H2O
(2) a stearidonoyl-[glycerolipid] + 2 ferrocytochrome b5 + O2 + 2 H+ = a (9Z,12Z,15Z)-octadeca-9,12,15-trien-6-ynoyl-[glycerolipid] + 2 ferricytochrome b5 + 2 H2O
Glossary: γ-linolenoate = (6Z,9Z,12Z)-octadeca-6,9,12-trienoate
stearidonate = (6Z,9Z,12Z,15Z)-octadeca-6,9,12,15-tetraenoate
dicranin = (9Z,12Z,15Z)-octadeca-9,12,15-trien-6-ynoic acid
Systematic name: Δ6 acyl-lipid,ferrocytochrome-b5:oxygen oxidoreductase (6,7-dehydrogenating)
Comments: The enzyme, characterized from the moss Ceratodon purpureus, converts the double bond at position 6 of γ-linolenate and stearidonate into a triple bond. The product of the latter, dicranin, is the main fatty acid found in C. purpureus. The enzyme contains a cytochrome b5 domain that acts as the direct electron donor to the desaturase active site. The enzyme also has the activity of EC 1.14.19.47, acyl-lipid (9-3)-desaturase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Sperling, P., Lee, M., Girke, T., Zähringer, U., Stymne, S. and Heinz, E. A bifunctional Δ6-fatty acyl acetylenase/desaturase from the moss Ceratodon purpureus. A new member of the cytochrome b5 superfamily. Eur. J. Biochem. 267 (2000) 3801-3811. [PMID: 10848999]
Accepted name: acyl-lipid Δ12-acetylenase
Reaction: linoleoyl-[glycerolipid] + 2 ferrocytochrome b5 + O2 + 2 H+ = crepenynyl-[glycerolipid] + 2 ferricytochrome b5 + 2 H2O
Glossary: crepenynate = (9Z)-octadec-9-en-12-ynoate
Systematic name: Δ12 acyl-lipid,ferrocytochrome-b5:oxygen oxidoreductase (12,13 dehydrogenating)
Comments: The enzyme, characterized from the plant Crepis alpina, converts the double bond at position 12 of linoleate into a triple bond. The product is the main fatty acid found in triacylglycerols in the seed oil of Crepis alpina.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Banas, A., Bafor, M., Wiberg, E., Lenman, M., Staahl, U. and Stymne, S. Biosynthesis of an acetylenic fatty acid in microsomal preparations from developing seeds Crepis alpina. Physiol. Biochem. Mol. Biol. Plant. [Proc. Int. Symp. Plant Lipids] 12th (1997) 57-59.
2. Lee, M., Lenman, M., Banas, A., Bafor, M., Singh, S., Schweizer, M., Nilsson, R., Liljenberg, C., Dahlqvist, A., Gummeson, P.O., Sjodahl, S., Green, A. and Stymne, S. Identification of non-heme di-iron proteins that catalyze triple bond and epoxy group formation. Science 280 (1998) 915-918. [PMID: 9572738]
3. Nam, J.W. and Kappock, T.J. Cloning and transcriptional analysis of Crepis alpina fatty acid desaturases affecting the biosynthesis of crepenynic acid. J. Exp. Bot. 58 (2007) 1421-1432. [PMID: 17329262]
Accepted name: hex-5-enoyl-[acyl-carrier protein] acetylenase
Reaction: hex-5-enoyl-[acyl-carrier protein] + 2 reduced ferredoxin [iron-sulfur] cluster + O2 + 2 H+ = hex-5-ynoyl-[acyl-carrier protein] + 2 oxidized ferredoxin [iron-sulfur] cluster + 2 H2O
Other name(s): jamB (gene name)
Systematic name: hex-5-enoyl-[acyl-carrier protein],reduced ferredoxin:oxygen oxidoreductase (5,6-dehydrogenating)
Comments: The enzyme, characterized from the marine cyanobacterium Moorea producens, is involved in production of the ion channel blocker jamaicamide A. It is specific for hexanoate or hex-5-enoate loaded onto a dedicated acyl-carrier protein (JamC), which is encoded by a gene in the same operon.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Zhu, X., Liu, J. and Zhang, W. De novo biosynthesis of terminal alkyne-labeled natural products. Nat. Chem. Biol. 11 (2015) 115-120. [PMID: 25531891]
Accepted name: sterol 22-desaturase
Reaction: ergosta-5,7,24(28)-trien-3β-ol + NADPH + H+ + O2 = ergosta-5,7,22,24(28)-tetraen-3β-ol + NADP+ + 2 H2O
For diagram of reaction click here.
Other name(s): ERG5 (gene name); CYP710A (gene name)
Systematic name: ergosta-5,7,24(28)-trien-3β-ol,NADPH:oxygen oxidoreductase 22,23-dehydrogenating
Comments: A heme-thiolate protein (P450). The enzyme, found in yeast and plants, catalyses the introduction of a double bond between the C-22 and C-23 carbons of certain sterols. In yeast the enzyme acts on ergosta-5,7,24(28)-trien-3β-ol, a step in the biosynthesis of ergosterol. The enzyme from the plant Arabidopsis thaliana acts on sitosterol and 24-epi-campesterol, producing stigmasterol and brassicasterol, respectively.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Kelly, S.L., Lamb, D.C., Corran, A.J., Baldwin, B.C., Parks, L.W. and Kelly, D.E. Purification and reconstitution of activity of Saccharomyces cerevisiae P450 61, a sterol Δ22-desaturase. FEBS Lett. 377 (1995) 217-220. [PMID: 8543054]
2. Skaggs, B.A., Alexander, J.F., Pierson, C.A., Schweitzer, K.S., Chun, K.T., Koegel, C., Barbuch, R. and Bard, M. Cloning and characterization of the Saccharomyces cerevisiae C-22 sterol desaturase gene, encoding a second cytochrome P-450 involved in ergosterol biosynthesis. Gene 169 (1996) 105-109. [PMID: 8635732]
3. Morikawa, T., Mizutani, M., Aoki, N., Watanabe, B., Saga, H., Saito, S., Oikawa, A., Suzuki, H., Sakurai, N., Shibata, D., Wadano, A., Sakata, K. and Ohta, D. Cytochrome P450 CYP710A encodes the sterol C-22 desaturase in Arabidopsis and tomato. Plant Cell 18 (2006) 1008-1022. [PMID: 16531502]
Accepted name: palmitoyl-[glycerolipid] 7-desaturase
Reaction: a 1-acyl-2-palmitoyl-[glycerolipid] + 2 reduced ferredoxin [iron-sulfur] cluster + O2 + 2 H+ = a 1-acyl-2-[(7Z)-hexadec-7-enoyl]-[glycerolipid] + 2 oxidized ferredoxin [iron-sulfur] cluster + 2 H2O
Other name(s): FAD5
Systematic name: 1-acyl-2-palmitoyl-[glycerolipid],ferredoxin:oxygen oxidoreductase (7,8-cis-dehydrogenating)
Comments: The enzyme introduces a cis double bond at carbon 7 of a palmitoyl group attached to the sn-2 position of glycerolipids. The enzyme from the plant Arabidopsis thaliana is specific for palmitate in monogalactosyldiacylglycerol.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Kunst, L., Browse, J., Somerville, C.R. A mutant of Arabidopsis deficient in desaturation of palmitic acid in leaf lipids. Plant Physiol. 90 (1989) 943-947.
2. Heilmann, I., Mekhedov, S., King, B., Browse, J. and Shanklin, J. Identification of the Arabidopsis palmitoyl-monogalactosyldiacylglycerol Δ7-desaturase gene FAD5, and effects of plastidial retargeting of Arabidopsis desaturases on the fad5 mutant phenotype. Plant Physiol. 136 (2004) 4237-4245. [PMID: 15579662]
Accepted name: palmitoyl-[glycerolipid] 3-(E)-desaturase
Reaction: a 1-acyl-2-palmitoyl-[glycerolipid] + 2 reduced ferredoxin [iron-sulfur] cluster + O2 + 2 H+ = a 1-acyl-2-[(3E)-hexadec-3-enoyl]-[glycerolipid] + 2 oxidized ferredoxin [iron-sulfur] cluster + 2 H2O
Other name(s): FAD4
Systematic name: 1-acyl-2-palmitoyl-[glycerolipid],ferredoxin:oxygen oxidoreductase (3,4-trans -dehydrogenating)
Comments: The enzyme introduces an unusual trans double bond at carbon 3 of a palmitoyl group attached to the sn-2 position of glycerolipids. The enzyme from the plant Arabidopsis thaliana is specific for palmitate in phosphatidylglycerol. The enzyme from tobacco can also accept oleate and α-linolenate if present at the sn-2 position of phosphatidylglycerol [1].
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Fritz, M., Lokstein, H., Hackenberg, D., Welti, R., Roth, M., Zähringer, U., Fulda, M., Hellmeyer, W., Ott, C., Wolter, F.P. and Heinz, E. Channeling of eukaryotic diacylglycerol into the biosynthesis of plastidial phosphatidylglycerol. J. Biol. Chem. 282 (2007) 4613-4625. [PMID: 17158889]
2. Gao, J., Ajjawi, I., Manoli, A., Sawin, A., Xu, C., Froehlich, J.E., Last, R.L. and Benning, C. FATTY ACID DESATURASE4 of Arabidopsis encodes a protein distinct from characterized fatty acid desaturases. Plant J. 60 (2009) 832-839. [PMID: 19682287]
Accepted name: acyl-CoA (8-3)-desaturase
Reaction: (1) (8Z,11Z,14Z)-icosa-8,11,14-trienoyl-CoA + 2 ferrocytochrome b5 + O2 + 2 H+ = arachidonoyl-CoA + 2 ferricytochrome b5 + 2 H2O
(2) (8Z,11Z,14Z,17Z)-icosa-8,11,14,17-tetraenoyl-CoA + 2 ferrocytochrome b5 + O2 + 2 H+ = (5Z,8Z,11Z,14Z,17Z)-icosa-5,8,11,14,17-pentaenoyl-CoA + 2 ferricytochrome b5 + 2 H2O
Other name(s): FADS1 (gene name); acyl-CoA 5-desaturase (methylene-interrupted)
Systematic name: Δ8-acyl-CoA,ferrocytochrome b5:oxygen oxidoreductase (5,6-cis-dehydrogenating)
Comments: The enzyme introduces a cis double bond at carbon 5 of acyl-CoAs that contain a double bond at position 8. The enzymes from algae, mosses, mammals and the protozoan Leishmania major catalyse the desaturation of dihomo-γ-linoleate [(8Z,11Z,14Z)-icosa-8,11,14-trienoate] and (8Z,11Z,14Z,17Z)-icosa-8,11,14,17-tetraenoate to generate arachidonate and (5Z,8Z,11Z,14Z,17Z)-icosa-5,8,11,14,17-pentaenoate, respectively. The enzyme contains a cytochrome b5 domain that acts as the direct electron donor to the desaturase active site and does not require an external cytochrome. cf. EC 1.14.19.37, acyl-CoA 5-desaturase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Cho, H.P., Nakamura, M. and Clarke, S.D. Cloning, expression, and fatty acid regulation of the human Δ5 desaturase. J. Biol. Chem. 274 (1999) 37335-37339. [PMID: 10601301]
2. Leonard, A.E., Kelder, B., Bobik, E.G., Chuang, L.T., Parker-Barnes, J.M., Thurmond, J.M., Kroeger, P.E., Kopchick, J.J., Huang, Y.S. and Mukerji, P. cDNA cloning and characterization of human Δ5-desaturase involved in the biosynthesis of arachidonic acid. Biochem. J. 347 Pt 3 (2000) 719-724. [PMID: 10769175]
3. Tripodi, K.E., Buttigliero, L.V., Altabe, S.G. and Uttaro, A.D. Functional characterization of front-end desaturases from trypanosomatids depicts the first polyunsaturated fatty acid biosynthetic pathway from a parasitic protozoan. FEBS J. 273 (2006) 271-280. [PMID: 16403015]
4. Tavares, S., Grotkjær, T., Obsen, T., Haslam, R.P., Napier, J.A. and Gunnarsson, N. Metabolic engineering of Saccharomyces cerevisiae for production of eicosapentaenoic acid, using a novel Δ5-desaturase from Paramecium tetraurelia. Appl. Environ. Microbiol. 77 (2011) 1854-1861. [PMID: 21193673]
Accepted name: sn-1 oleoyl-lipid 12-desaturase
Reaction: a 1-oleoyl-2-acyl-[glycerolipid] + 2 reduced ferredoxin [iron-sulfur] cluster + O2 + 2 H+ = a 1-linoleoyl-2-acyl-[glycerolipid] + 2 oxidized ferredoxin [iron-sulfur] cluster + 2 H2O
Other name(s): desA (gene name)
Systematic name: 1-oleoyl-2-acyl-[glycerolipid],ferredoxin:oxygen oxidoreductase (12,13-cis-dehydrogenating)
Comments: The enzyme, characterized from cyanobacteria, introduces a cis double bond at carbon 12 of oleoyl groups (18:1) attached to the sn-1 position of glycerolipids. The enzyme is a methyl-end desaturase, introducing the new double bond between a pre-existing double bond and the methyl-end of the fatty acid. It is nonspecific with respect to the polar head group of the glycerolipid.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Wada, H., Gombos, Z. and Murata, N. Enhancement of chilling tolerance of a cyanobacterium by genetic manipulation of fatty acid desaturation. Nature 347 (1990) 200-203. [PMID: 2118597]
2. Higashi, S. and Murata, N. An in vivo study of substrate specificities of acyl-lipid desaturases and acyltransferases in lipid synthesis in Synechocystis PCC6803. Plant Physiol. 102 (1993) 1275-1278. [PMID: 12231903]
3. Amiri, R.M., Yur'eva, N.O., Shimshilashvili, K.R., Goldenkova-Pavlova, I.V., Pchelkin, V.P., Kuznitsova, E.I., Tsydendambaev, V.D., Trunova, T.I., Los, D.A., Jouzani, G.S. and Nosov, A.M. Expression of acyl-lipid Δ12-desaturase gene in prokaryotic and eukaryotic cells and its effect on cold stress tolerance of potato. J Integr Plant Biol 52 (2010) 289-297. [PMID: 20377689]
Accepted name: sn-1 linoleoyl-lipid 6-desaturase
Reaction: a 1-linoleoyl-2-acyl-[glycerolipid] + 2 reduced ferredoxin [iron-sulfur] cluster + O2 + 2 H+ = a 1-γ-linolenoyl-2-acyl-[glycerolipid] + 2 oxidized ferredoxin [iron-sulfur] cluster + 2 H2O
Other name(s): desD (gene name)
Systematic name: 1-linoleoyl-2-acyl-[glycerolipid],ferredoxin:oxygen oxidoreductase (6,7-cis-dehydrogenating)
Comments: The enzyme, characterized from cyanobacteria, introduces a cis double bond at carbon 6 of linoleoyl groups (18:2) attached to the sn-1 position of glycerolipids. The enzyme is a front-end desaturase, introducing the new double bond between a pre-existing double bond and the carboxyl-end of the fatty acid. It is nonspecific with respect to the polar head group of the glycerolipid.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Higashi, S. and Murata, N. An in vivo study of substrate specificities of acyl-lipid desaturases and acyltransferases in lipid synthesis in Synechocystis PCC6803. Plant Physiol. 102 (1993) 1275-1278. [PMID: 12231903]
2. Reddy, A.S. and Thomas, T.L. Expression of a cyanobacterial Δ6-desaturase gene results in γ-linolenic acid production in transgenic plants. Nat. Biotechnol. 14 (1996) 639-642. [PMID: 9630958]
3. Kurdrid, P., Subudhi, S., Hongsthong, A., Ruengjitchatchawalya, M. and Tanticharoen, M. Functional expression of Spirulina-Δ6 desaturase gene in yeast, Saccharomyces cerevisiae. Mol. Biol. Rep. 32 (2005) 215-226. [PMID: 16328883]
Accepted name: acyl-lipid (9-3)-desaturase
Reaction: (1) an α-linolenoyl-[glycerolipid] + 2 ferrocytochrome b5 + O2 + 2 H+ = a stearidonoyl-[glycerolipid] + 2 ferricytochrome b5 + 2 H2O
(2) a linoleoyl-[glycerolipid] + 2 ferrocytochrome b5 + O2 + 2 H+ = a γ-linolenoyl-[glycerolipid] + 2 ferricytochrome b5 + 2 H2O
Glossary: stearidonic acid = (6Z,9Z,12Z,15Z)-octadeca-6,9,12,15-tetraenoic acid
Other name(s): DES6 (gene name); acyl-lipid 6-desaturase; acyl-lipid Δ6-desaturase; Δ6-desaturase (ambiguous)
Systematic name: Δ9 acyl-[glycerolipid],ferrocytochrome b5:oxygen oxidoreductase (6,7-cis-dehydrogenating)
Comments: The enzyme, characterized from the moss Physcomitrella patens and the plant Borago officinalis (borage), introduces a cis double bond at carbon 6 of several acyl-lipids that contain an existing Δ9 cis double bond. The enzyme contains a cytochrome b5 domain that acts as the electron donor for the active site of the desaturase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Sayanova, O., Smith, M.A., Lapinskas, P., Stobart, A.K., Dobson, G., Christie, W.W., Shewry, P.R. and Napier, J.A. Expression of a borage desaturase cDNA containing an N-terminal cytochrome b5 domain results in the accumulation of high levels of Δ6-desaturated fatty acids in transgenic tobacco. Proc. Natl. Acad. Sci. USA 94 (1997) 4211-4216. [PMID: 9108131]
2. Girke, T., Schmidt, H., Zähringer, U., Reski, R. and Heinz, E. Identification of a novel Δ6-acyl-group desaturase by targeted gene disruption in Physcomitrella patens. Plant J. 15 (1998) 39-48. [PMID: 9744093]
Accepted name: tert-amyl alcohol desaturase
Reaction: tert-amyl alcohol + NADPH + H+ + O2 = isoprenyl alcohol + NADP+ + 2 H2O
Glossary: isoprenyl alcohol = 3-methylbut-1-en-3-ol
tert-amyl alcohol = 2-methylbutan-2-ol
Other name(s): mdpJK (gene names)
Systematic name: tert-amyl alcohol,NADPH:oxygen oxidoreductase (1,2-dehydrogenating)
Comments: The enzyme, characterized from the bacterium Aquincola tertiaricarbonis, is a Rieske nonheme mononuclear iron oxygenase. It can also act, with lower efficiency, on butan-2-ol, converting it to but-1-en-3-ol. Depending on the substrate, the enzyme also catalyses EC 1.14.13.229, tert-butyl alcohol monooxygenase.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:
References:
1. Schafer, F., Schuster, J., Wurz, B., Hartig, C., Harms, H., Muller, R.H. and Rohwerder, T. Synthesis of short-chain diols and unsaturated alcohols from secondary alcohol substrates by the Rieske nonheme mononuclear iron oxygenase MdpJ. Appl. Environ. Microbiol. 78 (2012) 6280-6284. [PMID: 22752178]
2. Schuster, J., Schafer, F., Hubler, N., Brandt, A., Rosell, M., Hartig, C., Harms, H., Muller, R.H. and Rohwerder, T. Bacterial degradation of tert-amyl alcohol proceeds via hemiterpene 2-methyl-3-buten-2-ol by employing the tertiary alcohol desaturase function of the Rieske nonheme mononuclear iron oxygenase MdpJ. J. Bacteriol. 194 (2012) 972-981. [PMID: 22194447]
Accepted name: tetracycline 7-halogenase
Reaction: tetracycline + FADH2 + chloride + O2 + H+ = 7-chlorotetracycline + FAD + 2 H2O
For diagram of reaction click here.
Other name(s): ctcP (gene name)
Systematic name: tetracycline:FADH2 oxidoreductase (7-halogenating)
Comments: The enzyme, characterized from the bacterium Streptomyces aureofaciens, is a member of the flavin-dependent halogenase family. The enzyme forms a lysine chloramine intermediate on an internal lysine residue before transferring the chlorine to the substrate. It is stereo-selective for the 4S (natural) isomer of tetracycline. FADH2 is provided by a dedicated EC 1.5.1.36, flavin reductase (NADH).
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:
References:
1. Dairi, T., Nakano, T., Aisaka, K., Katsumata, R. and Hasegawa, M. Cloning and nucleotide sequence of the gene responsible for chlorination of tetracycline. Biosci. Biotechnol. Biochem. 59 (1995) 1099-1106. [PMID: 7612997]
2. Zhu, T., Cheng, X., Liu, Y., Deng, Z. and You, D. Deciphering and engineering of the final step halogenase for improved chlortetracycline biosynthesis in industrial Streptomyces aureofaciens. Metab. Eng. 19 (2013) 69-78. [PMID: 23800859]
Accepted name: noroxomaritidine synthase
Reaction: (1) 4'-O-methylnorbelladine + [reduced NADPH—hemoprotein reductase] + O2 = (4aR,10bS)-noroxomaritidine + [oxidized NADPH—hemoprotein reductase] + 2 H2O
(2) 4'-O-methylnorbelladine + [reduced NADPH—hemoprotein reductase] + O2 = (4aS,10bR)-noroxomaritidine + [oxidized NADPH—hemoprotein reductase] + 2 H2O
For diagram of reaction click here.
Glossary: 4'-O-methylnorbelladine = 5-({[2-(4-hydroxyphenyl)ethyl]amino}methyl)-2-methoxyphenol
noroxomaritidine = 8-hydroxy-9-methoxy-4,4a-dihydro-3H,6H-5,10b-ethanophenanthridin-3-one
Other name(s): CYP96T1 (gene name)
Systematic name: 4'-O-methylnorbelladine,NADPH—hemoprotein reductase:oxygen oxidoreductase (noroxomaritidine-forming)
Comments: A P-450 (heme-thiolate) enzyme. The enzyme, characterized from Narcissus pseudonarcissus (daffodil), forms the two enantiomers of the Amaryllidacea alkaloid noroxomaritidine by catalysing intramolecular oxidative para-para' phenol coupling. The oxidation involves molecular oxygen without its incorporation into the product.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:
References:
1. Kilgore, M.B., Augustin, M.M., May, G.D., Crow, J.A. and Kutchan, T.M. CYP96T1 of Narcissus sp. aff. pseudonarcissus catalyzes formation of the para-para' C-C phenol couple in the Amaryllidaceae alkaloids. Front. Plant Sci. 7 (2016) 225. [PMID: 26941773]