Acyltransferases and methods of using

A method of producing triacylglycerols (TAGs) comprising medium-chain fatty acids (MCFAs) in an organism, comprising:

• introducing a first transgene into the organism, wherein the first transgene comprises at least one nucleic acid sequence encoding a lysophosphatidic acid acyltransferase (LPAT), wherein the LPAT exhibits a substrate specificity for saturated fatty acids, and wherein the LPAT has at least 90% sequence identity to SEQ ID NO:2 or SEQ ID NO:4, and wherein said LPAT comprises motif I [NH(X)4D], motif II (LPVLGW) (SEQ ID NO:
• 47), motif III (FPEGTR) (SEQ ID NO:
• 45), motif IV (NVLIPRTKGFV) (SEQ ID NO:
• 48), and motif V IMRSFVPA(X)YD(X)TVI;
• and
• introducing a second transgene into the organism, wherein the second transgene comprises at least one nucleic acid sequence encoding a diacylglycerol acyltransferase (DGAT), wherein the DGAT exhibits a substrate specificity for saturated fatty acids, and wherein the DGAT has at least 90% sequence identity to SEQ ID NO:8, and wherein said DGAT comprises an arginine at residue number 91, an asparagine at residue number 97, and a glutamate at residue number 99;
• thereby producing TAGs comprising MCFAs in the organism, wherein the organism is a plant or a microbe.