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]