Acyltransferase that appears to be required for E.coli optimal growth rate and yield via the formation of N-acetylated amino acids. Catalyzes the acylation of L-methionine using acetyl-CoA or propanoyl-CoA as acyl donors, and the acetylation of L-phenylglycine (PubMed:27941785). Is also able to N-acylate other free L-amino acids and their derivatives using a CoA thioester as cosubstrate. Using acetyl-CoA as an acyl donor, substrate specificity is methionine sulfone > methionine sulfoximine > methionine sulfoxide > methionine. Asparagine, lysine, glutamine, aspartate and glutamate are very poor substrates. Using methionine as a substrate, acyl donor preference is propanoyl-CoA > acetyl-CoA >> butyryl-CoA (Ref.4). Likely plays a role in the resistance against the toxic effects of L-methionine sulfoximine (MSX), via its ability to catalyze its acetylation; MSX is a rare amino acid which inhibits glutamine synthetase (GlnA) (By similarity). acetyl-CoA + L-methionine = CoA + H(+) + N(alpha)-acetyl-L-methionine L-methionine + propanoyl-CoA = CoA + H(+) + N-propanoyl-L-methioninate acetyl-CoA + L-alpha-phenylglycine = CoA + H(+) + N-acetyl-L-alpha-phenylglycine acetyl-CoA + L-methionine sulfoximine = CoA + H(+) + N-acetyl-L-methionine sulfoximine acetyl-CoA + L-methionine sulfone = CoA + H(+) + N-acetyl-L-methionine sulfone Cells lacking this gene show a reduced growth rate and a markedly reduced yield in glucose minimal medium compared to wild-type; this phenotype can be partially rescued by adding L-phenylglycine to the medium, which reflects that other enzymes may also catalyze its acetylation, but with lower affinities. The deletion mutant strain also shows a consistent change in the level of several metabolites whose masses can correspond to L-phenylglycine, L-pipecolate or N4-acetylaminobutanal. Expression leads to increased levels of N-acylated L-amino acids which could be used in a number of applications. Belongs to the acetyltransferase family. PAT/BAR subfamily.