pH-dependent regulation of an acidophilic -acetylhomoserine sulfhydrylase from .

Unlabelled: Bacteria have two routes for the l-methionine biosynthesis. In one route called the direct sulfuration pathway, acetylated l-homoserine is directly converted into l-homocysteine. The reaction using HS as the second substrate is catalyzed by a pyridoxal 5'-phosphate-dependent enzyme, -acetylhomoserine sulfhydrylase (OAHS).