The present invention relates to a method of producing a variant lipid acyltransferase enzyme comprising: (a) selecting a parent enzyme which is a lipid acyltransferase enzyme characterised in that the enzyme comprises the amino acid sequence motif GDSX, wherein X is one or more of the following amino acid residues L, A, V, I, F, Y, H, Q, T N, M or S; (b) modifying one or more amino acids to produce a variant lipid acyltransferase; (c) testing the variant lipid acyltransferase for activity on a galactolipid substrate, and optionally a phospholipid substrate and/or optionally a triglyceride substrate; (d) selecting a variant enzyme with an enhanced activity towards galactolipids compared with the parent enzyme; and optionally (e) preparing a quantity of the variant enzyme. The present invention further relates to variant lipid acyltransferase enzyme characterised in that the enzyme comprises the amino acid sequence motif GDSX, wherein X is one or more of the following amino acid residues L, A, V, I, F, Y, H, Q, T N, M or S, and wherein the variant enzyme comprises one or more amino acid modifications compared with a parent sequence at any one or more of the following amino acid residues when aligned to SEQ ID No. 2: Ser3, Leu17, Ala114, Trp111, Tyr117, Leu118, Pro156, Gly159, Gln160, Asn161, Pro162, Ser163, Ala164, Arg165, Ser166, Gln167, Lys168, Val169, Val170, Glu171, Ala172, Tyr179, Gln182, Lys187, His180, Asn181, Met209, Leu210, Arg211, Asn215, Lys284, Met285, Gln289, Val290, Ala309, Ser310, Lys22, Met23, Gly40, Asn80, Pro81, Lys82, Val112, Asn87, Asn88, −318.