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]