-!- Exhibits a marked preference for [acyl-carrier-protein] derivatives over CoA derivatives as substrates.

-!- Responsible for the chain-elongation step of dissociated (type II) fatty-acid biosynthesis, i.e. the addition of two C atoms to the fatty-acid chain. -!- Escherichia coli mutants that lack this enzyme are deficient in unsaturated fatty acids. -!- Can use fatty acyl thioesters of ACP (C(2) to C(16)) as substrates, as well as fatty acyl thioesters of Co-A (C(4) to C(16)). -!- The substrate specificity is very similar to that of EC 2.3.1.179 with the exception that the latter enzyme is far more active with palmitoleoyl-ACP (C(16)-Delta(9)) as substrate, allowing the organism to regulate its fatty-acid composition with changes in temperature.

-!- The enzyme from yeasts (Ascomycota and Basidiomycota) is a multi- functional protein complex composed of two subunits. -!- One subunit catalyzes the reactions EC 1.1.1.100 and EC 2.3.1.41, while the other subunit catalyzes the reactions of EC 2.3.1.38, EC 2.3.1.39, EC 4.2.1.59, EC 1.3.1.10 and EC 1.1.1.279. -!- The enzyme differs from the animal enzyme (EC 2.3.1.85) in that the enoyl reductase domain requires FMN as a cofactor, and the ultimate product is an acyl-CoA (usually palmitoyl-CoA) instead of a free fatty acid.