Upon expression in E.coli has a weak triacylglycerol synthase function, making triacylglycerol (TG) from diolein and long-chain fatty acyl-CoA. Also functions weakly as a wax synthase, as it incorporates palmityl alcohol into wax esters in the presence of palmitoyl-CoA. a 1,2-diacyl-sn-glycerol + an acyl-CoA = a triacyl-sn-glycerol + CoA (9Z)-octadecenoyl-CoA + di-(9Z)-octadecenoylglycerol = 1,2,3-tri-(9Z-octadecenoyl)-glycerol + CoA hexadecan-1-ol + hexadecanoyl-CoA = CoA + hexadecanyl hexadecanoate Glycerolipid metabolism; triacylglycerol biosynthesis. Constitutively expressed at a low level, it is not further induced by hypoxia or nitric oxide exposure. Belongs to the long-chain O-acyltransferase family.