Catalyzes the terminal and only committed step in triacylglycerol synthesis by using diacylglycerol and fatty acyl CoA as substrates. a 1,2-diacyl-sn-glycerol + an acyl-CoA = a triacyl-sn-glycerol + CoA all-trans-retinol + an acyl-CoA = an all-trans-retinyl ester + CoA (9Z)-octadecenoyl-CoA + 2-(9Z-octadecenoyl)-glycerol = 1,2-di-(9Z-octadecenoyl)-sn-glycerol + CoA (9Z)-octadecenoyl-CoA + 1,2-di-(9Z-octadecenoyl)-sn-glycerol = 1,2,3-tri-(9Z-octadecenoyl)-glycerol + CoA all-trans-retinol + hexadecanoyl-CoA = all-trans-retinyl hexadecanoate + CoA (9Z)-octadecenoyl-CoA + 1-O-(9Z-octadecenyl)-glycerol = 1-O-(9Z-octadecenyl)-mono-(9Z-octadecenoyl)-glycerol + CoA (9Z)-octadecenoyl-CoA + 1-O-(9Z-octadecenyl)-mono-(9Z-octadecenoyl)-glycerol = 1-O-(9Z-octadecenyl)-2,3-di-(9Z-octadecenoyl)glycerol + CoA (9Z)-octadecenoyl-CoA + 1-(9Z-octadecenoyl)-glycerol = 1,2-di-(9Z-octadecenoyl)-glycerol + CoA (9Z)-octadecenoate + 1,2-di-(9Z-octadecenoyl)-glycerol + H(+) = 1,2,3-tri-(9Z-octadecenoyl)-glycerol + H2O (9Z)-octadecenoyl-CoA + 1-octadecanoyl-2-(5Z,8Z,11Z,14Z-eicosatetraenoyl)-sn-glycerol = 1-octadecanoyl-2-(5Z,8Z,11Z,14Z)-eicosatetraenoyl-3-(9Z)-octadecenoyl-sn-glycerol + CoA hexadecane-1,2-diol + 2 hexadecanoyl-CoA = 1,2-O,O-dihexadecanoyl-1,2-hexadecanediol + 2 CoA hexadecane-1,2-diol + hexadecanoyl-CoA = 2-hydroxyhexadecyl hexadecanoate + CoA 2-(9Z-octadecenoyl)-glycerol + hexadecanoyl-CoA = 1-hexadecanoyl-2-(9Z-octadecenoyl)-sn-glycerol + CoA 1,2-di-(9Z-octadecenoyl)-sn-glycerol + hexadecanoyl-CoA = 1,2-di-(9Z)-octadecenoyl-3-hexadecanoyl-sn-glycerol + CoA hexadecan-1-ol + hexadecanoyl-CoA = CoA + hexadecanyl hexadecanoate 13-cis-retinol + hexadecanoyl-CoA = 13-cis-retinyl hexadecanoate + CoA (9Z)-octadecenoyl-CoA + 1,3-di-(9Z-octadecenoyl)-glycerol = 1,2,3-tri-(9Z-octadecenoyl)-glycerol + CoA (9Z)-octadecenoyl-CoA + 2,3-di-(9Z)-octadecenoyl-sn-glycerol = 1,2,3-tri-(9Z-octadecenoyl)-glycerol + CoA Lipid metabolism; glycerolipid metabolism. Belongs to the membrane-bound acyltransferase family. Sterol o-acyltransferase subfamily.