Catalyzes the transfer of an acetyl group from acetyl coenzyme A (AcCoA) to an acceptor substrate and releases both CoA and the acetylated product. It prefers L-threonine, L-serine and L-methionine. It can also use O-acetyl-L-serine, L-tryptophan, L-isoleucine, L-valine, L-homoserine, 7-aminocephalosporanic acid, thiamine pyrophosphate and thiamine.