Acyl-CoA-dependent acyltransferase; part of the gene cluster that mediates the biosynthesis of mannosylerythritol lipids (MELs), surface-active substances that enhance the availability of water-insoluble substrates (PubMed:15932999, PubMed:16885300). Mannosylerythritol lipid production is responsible for hemolytic activity of Ustilago maydis (PubMed:15932999). Depending on the number of acetyl groups, mannosylerythritol lipids can be differentiated into MEL A (fully acetylated), MEL B and MEL C (monoacetylated at R-6 and R-4, respectively), and the fully deacetylated MEL D (PubMed:31103599). The first step in the pathway is the generation of mannosylerythritol by the glycosyltransferase EMT1 which catalyzes the transfer of GDP-mannose to the C-4 atom of meso-erythritol (PubMed:15932999). This reaction has to be stereospecific, since only mannosyl-D-erythritol is generated (PubMed:15932999). The produced disaccharide is subsequently acylated with fatty acids of various lengths derived from the peroxisomal beta-oxidation by the peroxisomal acyltransferases MAC1 and MAC2 at positions C-2 and C-3, repectively (PubMed:16885300, PubMed:24835306, PubMed:31103599). The existence of MEL derivatives which carry an acetyl group at C-2 implies that at least MAC1 also accepts acetyl-CoA as a donor (PubMed:15932999). The final step of MEL biosynthesis is the acetylation of the fully acylated mannosylerythritol lipids catalyzed by the acetyl-CoA-dependent acetyltransferase MAT1 (PubMed:16885300). MAT1 displays a relaxed regioselectivity and is able to transfer acetylgroups to both positions C-4 and C-6 of the mannosyl moiety (PubMed:15932999). Secondary metabolite biosynthesis. The C-terminal PTS1-type tripeptide peroxisomal targeting signal is required for the import into peroxisomes. Abolishes completely the production of mannosylerythritol lipids (MELs). MELs not only have high potential as eco-friendly biosurfactants due to their excellent surface activity, but also have attracted considerable recent interest because of thei runique properties, including self-assembly, anti-tumor and cell differentiation induction activities, and moisturizing and hair-repairing properties. Belongs to the trichothecene O-acetyltransferase family.