Transfers an acetyl group from acetyl-CoA to L-homoserine, forming acetyl-L-homoserine. acetyl-CoA + L-homoserine = CoA + O-acetyl-L-homoserine Amino-acid biosynthesis; L-methionine biosynthesis via de novo pathway; O-acetyl-L-homoserine from L-homoserine: step 1/1. Homodimer. In the N-terminal section; belongs to the AB hydrolase superfamily. MetX family. In the C-terminal section; belongs to the MetW family.