4zyb
From Proteopedia
High resolution structure of M23 peptidase LytM with substrate analogue
Structural highlights
FunctionLYTM_STAA8 Peptidoglycan hydrolase (autolysin) specifically acting on polyglycine interpeptide bridges of the cell wall peptidoglycan.[1] [2] Publication Abstract from PubMedLytM is a Staphylococcus aureus autolysin and a homologue of the S. simulans lysostaphin. Both enzymes are members of M23 metallopeptidase family (MEROPS) comprising primarily bacterial peptidoglycan hydrolases. LytM occurs naturally in a latent form, but can be activated by cleavage of an inhibitory N-terminal proregion. Here, we present a 1.45 A crystal structure of LytM catalytic domain with a transition state analogue, tetraglycine phosphinate, bound in the active site. In the electron density, the active site of the peptidase, the phosphinate and the "diglycine" fragment on the P1' side of the transition state analogue are very well defined. The density is much poorer or even absent for the P1 side of the ligand. The structure is consistent with the involvement of His260 and/or His291 in the activation of the water nucleophile and suggests a possible catalytic role for Tyr204, which we confirmed by mutagenesis. Possible mechanisms of catalysis and the structural basis of substrate specificity are discussed based on the structure analysis. High resolution structure of an M23 peptidase with a substrate analogue.,Grabowska M, Jagielska E, Czapinska H, Bochtler M, Sabala I Sci Rep. 2015 Oct 6;5:14833. doi: 10.1038/srep14833. PMID:26437833[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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