ID 1.14.19.44 DE acyl-CoA (8-3)-desaturase. AN acyl-CoA 5-desaturase (methylene-interrupted). CA (1) (8Z,11Z,14Z)-eicosatrienoyl-CoA + 2 Fe(II)-[cytochrome b5] + 2 H(+) + CA O2 = (5Z,8Z,11Z,14Z)-eicosatetraenoyl-CoA + 2 Fe(III)-[cytochrome b5] + CA 2 H2O. CA (2) (8Z,11Z,14Z,17Z)-eicosatetraenoyl-CoA + 2 Fe(II)-[cytochrome b5] + CA 2 H(+) + O2 = (5Z,8Z,11Z,14Z,17Z)-eicosapentaenoyl-CoA + 2 Fe(III)- CA [cytochrome b5] + 2 H2O. CC -!- The enzyme introduces a cis double bond at carbon 5 of acyl-CoAs that CC contain a double bond at position 8. CC -!- The enzymes from algae, mosses, mammals and the protozoan Leishmania CC major catalyze the desaturation of dihomo-gamma-linoleate CC ((8Z,11Z,14Z)-icosa-8,11,14-trienoate) and (8Z,11Z,14Z,17Z)-icosa- CC 8,11,14,17-tetraenoate to generate arachidonate and CC (5Z,8Z,11Z,14Z,17Z)-icosa-5,8,11,14,17-pentaenoate, respectively. CC -!- The enzyme contains a cytochrome b5 domain that acts as the direct CC electron donor to the desaturase active site and does not require an CC external cytochrome. cf. EC 1.14.19.37. DR B2KKL4, FAD1_SIGCA ; D8X2C5, FAD2_SIGCA ; O60427, FADS1_HUMAN; DR Q920L1, FADS1_MOUSE; A4UVI1, FADS1_PAPAN; Q920R3, FADS1_RAT ; DR Q9DEX7, FADS2_DANRE; G5EG11, FAT4_CAEEL ; //