acyltransferase

An acyltransferase is an enzyme that catalyzes the transfer of an acyl group from one molecule, the donor, to another, the acceptor. Acyltransferases comprise numerous subfamilies that use various acyl donors, most commonly acyl-CoA thioesters or acyl carrier protein (ACP) linked groups, and transfer the acyl to alcohols, amines, thiols, glycerols, cholesterol, or proteins. Reactions proceed by direct transfer or via a covalent acyl-enzyme intermediate, and are often highly specific for donor and acceptor substrates. These enzymes play central roles in lipid metabolism, protein modification, and secondary metabolite biosynthesis.

Representative examples include cholesterol acyltransferases (ACAT1/ACAT2), which synthesize cholesteryl esters; diacylglycerol acyltransferases (DGAT1/DGAT2), key steps in triacylglycerol formation; glycerol-3-phosphate acyltransferases (GPATs), initiating glycerolipid assembly; acyltransferases involved in protein modification such as N-myristoyltransferases, which attach myristoyl groups to N-terminal glycine residues; histone acetyltransferases, which modify chromatin by transferring acetyl groups from acetyl-CoA to lysine residues on histones. In plants and microbes, acyltransferases contribute to cuticle formation, wax synthesis, and antimicrobial metabolite production.

Clinical and industrial relevance: due to involvement in lipid storage, membrane composition, and gene regulation, acyltransferases are targets for therapies for metabolic diseases, cancer, and infectious diseases. They are also used in biotechnology to tailor lipid profiles in microorganisms or to produce modified natural products. Enzyme families are diverse, with structural motifs such as GNAT, MBOAT, and SGNH hydrolase-like folds described among acyltransferases.