Transfers an acetyl group from acetyl-CoA to L-homoserine, forming acetyl-L-homoserine (PubMed:17927957, PubMed:28581482). Utilizes a ping-pong kinetic mechanism in which the acetyl group of acetyl-CoA is initially transferred to the enzyme to form an acetyl-enzyme intermediate before subsequent transfer to homoserine to form the final product, O-acetylhomoserine (PubMed:17927957). 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. Belongs to the AB hydrolase superfamily. MetX family.