Novel acetyl-transferases

A modified acetyl transferase EC 2.3.1.84] with activity towards acetylation of retinol into retinyl acetate, wherein upon expression of said modified enzyme in a suitable retinol-producing Yarrowia strain the percentage of retinyl acetate is increased by at least 10-20 wt % as compared to the process using the same conditions but expressing the respective or corresponding enzyme according to SEQ ID NO:1, said modified acetyl transferase:

• (a) is based on an enzyme with at least 45% sequence identity to Lachancea mirantina ATF1 according to SEQ ID NO:1,
• (b) comprising a 7 amino acid motif N-H-x(3)-D-[GA], wherein “x” denotes an arbitrary amino acid, and wherein said motif corresponding to position N218 to G224 in the polypeptide according to SEQ ID NO:1;
• (c) comprising at least one amino acid substitution in an amino acid residue corresponding to position 451, 473, and/or 483 in the polypeptide according to SEQ ID NO:1, said amino acid substitution being selected from T473A, L483M, A451L, and/or A451M;
• with the proviso that amino acid residue corresponding to position 69 in SEQ ID NO:1 is either histidine or alanine, amino acid residue corresponding to position 407 in SEQ ID NO:1 is either valine or isoleucine, amino acid residue corresponding to position 409 in SEQ ID NO:1 is either glycine or alanine, amino acid corresponding to position 480 is either serine or glutamine, amino acid residue corresponding to position 484 in SEQ ID NO:1 is either isoleucine or leucine.