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]