This domain is found in the C-terminal region of [Acyl-carrier-protein] S-malonyltransferase from Bacillus velezensis (FabD) and similar bacterial proteins. FabD, a marine polyunsaturated fatty acid (PUFA) synthase involved in difficidin A biosynthesis, is is organised into two domains: anacetyl-transferase (AT) domain (Pfam:PF00698) and an enoyl reductase (ER) domain that consists of a TIM-barrel domain (Pfam:PF03060) and an inserted alpha-helical substrate-binding domain (this entry).

1: Evolutionary origins of the multienzyme architecture of giant fungal fatty acid synthase. Bukhari HST, Jakob RP, Maier T; Structure. 2014;22:1775-1785. PMID:25456814

2: Structural Insights into the Trans-Acting Enoyl Reductase in the Biosynthesis of Long-Chain Polyunsaturated Fatty Acids in Shewanella A1S4L3piezotolerans. Zhang M, Zhang H, Li Q, Gao Y, Guo L, He L, Zang S, Guo X, Huang J, Li L; J Agric Food Chem. 2021;69:2316-2324. PMID:33587627