8yxn

Publication Abstract from PubMed

Clostridioides difficile endolysin (Ecd09610) consists of an unknown domain at its N terminus, followed by two catalytic domains, a glucosaminidase domain and endopeptidase domain. X-ray structure and mutagenesis analyses of the Ecd09610 catalytic domain with glucosaminidase activity (Ecd09610CD53) were performed. Ecd09610CD53 was found to possess an alpha-bundle-like structure with nine helices, which is well conserved among GH73 family enzymes. The mutagenesis analysis based on X-ray structures showed that Glu405 and Asn470 were essential for enzymatic activity. Ecd09610CD53 may adopt a neighboring-group mechanism for a catalytic reaction in which Glu405 acted as an acid/base catalyst and Asn470 helped to stabilize the oxazolinium ion intermediate. Structural comparisons with the newly identified Clostridium perfringens autolysin catalytic domain (AcpCD) in the P1 form and a zymography analysis demonstrated that AcpCD was 15-fold more active than Ecd09610CD53. The strength of the glucosaminidase activity of the GH73 family appears to be dependent on the depth of the substrate-binding groove.

X-ray structure and mutagenesis analyses of Clostridioides difficile endolysin Ecd09610 glucosaminidase domain.,Sekiya H, Nonaka Y, Kamitori S, Miyaji T, Tamai E Biochem Biophys Res Commun. 2024 Jun 30;715:149957. doi: , 10.1016/j.bbrc.2024.149957. Epub 2024 Apr 16. PMID:38688057^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.