Identification of O‐acetylhomoserine sulfhydrylase, a putative enzyme responsible for methionine biosynthesis in Clostridioides difficile: Gene cloning and biochemical characterizations

Le résumé fourni par la source

Abstract O‐acetylhomoserine sulfhydrylase (OAHS) is a pyridoxal 5′‐phosphate‐dependent enzyme involved in microbial methionine biosynthesis. In this study, we report gene cloning, protein purification, and some biochemical characteristics of OAHS from Clostridioides difficile. The enzyme is a tetramer with molecular weight of 185 kDa. It possesses a high activity in the reaction of L‐homocysteine synthesis, comparable to reported activities of OAHSes from other sources. OAHS activity is inhibited by metabolic end product L‐methionine. L‐Propargylglycine was found to be a suicide inhibitor of the enzyme. Substrate analogue Nγ‐acetyl‐L‐2,4‐diaminobutyric acid is a competitive inhibitor of OAHS with Ki = 0.04 mM. Analysis of C. difficile genome allows to suggest that the bacterium uses the way of direct sulfhydrylation for the synthesis of L‐methionine. The data obtained may provide the basis for further study of the role of OAHS in the pathogenic bacterium and the development of potential inhibitors.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.