Proteins

The present invention relates to a method of producing a variant glycolipid acyltransferase enzyme comprising: (a) selecting a parent enzyme which is a glycolipid 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 glycolipid acyltransferase; (c) testing the variant glycolipid acyltransferase for transferase activity, an optionally hydrolytic 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 amino acid residues defined in set 2, set 4, set 6 or set 7.