This domain is found in wax ester synthases/diacylglycerol O-acyltransferases (WS/DAGs), largely found in bacteria, plants and animals. They catalyse the condensation of a fatty alcohol and a fatty acyl-Coenzyme A (acyl-CoA) and they can also catalyse the transesterification of acyl-CoAs with diacylglycerols. These are bifunctional enzymes (WS/DAGs) that share low overall sequence similarity but all WS/DGATs share a conserved HHXXXDG motif, which is also found in other acyltransferases [1,2]. This entry represents the N-terminal catalytic domain of WS/DAGs which contains the conserved HHXXXDG motif. It consists of a mixed beta-sheet flanked by four alpha-helices and a small antiparallel beta-sheet [2].

1: A novel bifunctional wax ester synthase/acyl-CoA:diacylglycerol acyltransferase mediates wax ester and triacylglycerol biosynthesis in Acinetobacter calcoaceticus ADP1. Kalscheuer R, Steinbuchel A; J Biol Chem. 2003;278:8075-8082. PMID:12502715

2: Structural and Biochemical Studies of a Biocatalyst for the Enzymatic Production of Wax Esters. Petronikolou N, Nair SK; ACS Catal. 2018;8:6334-6344. PMID:31559109