EC Explorer

1.14.19.44

acyl-CoA (8-3)-desaturase

(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

FADS1 (gene name), acyl-CoA 5-desaturase (methylene-interrupted)

Δ⁸-acyl-CoA,ferrocytochrome b₅:oxygen oxidoreductase (5,6-cis-dehydrogenating)

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.

created 2015