The present invention relates to a method of producing a variant lipid acyltransferase enzyme by selecting a parent enzyme which is a lipid acyltransferase enzyme having the amino acid sequence motif GDSX, modifying one or more amino acids to produce a variant lipid acyltransferase, testing the variant lipid acyltransferase for activity on a galactolipid substrate, a phospholipid substrate and/or a triglyceride substrate, selecting a variant enzyme with an enhanced activity towards galactolipids compared with the parent enzyme, and/or preparing a quantity of the variant enzyme. In some embodiments, the variant lipid acyltransferase enzyme may include the amino acid sequence motif GDSX, wherein X is one or more of the following amino acid residues L, A, V, I, F, Y, X, Q, T N, M or S, and wherein the variant enzyme has one or more amino acid modifications compared with a parent sequence.