4ly4
From Proteopedia
Crystal structure of peptidoglycan deacetylase (HP0310) with Zinc from Helicobacter pylori
Structural highlights
FunctionPGDAE_HELPG Catalyzes the N-deacetylation of peptidoglycan (PG), an important mechanism that appears to confer lysozyme resistance and to mitigate host immune detection; this likely contributes to pathogen persistence in the host. The exact nature of the residue in PG that is deacetylated has not been determined. Is also able to catalyze the deacetylation of acetylated xylan, and, to a lesser extent, that of chitin and chitosan. Therefore, this enzyme might play a role during infection, considering that xylan-containing carbohydrate structures are among those commonly consumed by humans (By similarity). In vitro, does not show activity on N-acetylglucosamine (GlcNAc), chitotriose (GlcNAc3), some N-acetyl-dipeptides and allantoinase.[1] Publication Abstract from PubMedPeptidoglycan deacetlyase (HP0310, HpPgdA) from the gram-negative pathogen Helicobacter pylori, is the enzyme responsible for a peptidoglycan modification that counteracts the host immune response. In a recent study, we determined the crystallographic structure of the enzyme, which is a homo-tetramer (Shaik et al., PloS One 2011;6:e19207). The metal-binding site, which is essential for the enzyme's catalytic activity, is visible within the structure, but we were unable to identify the nature of the metal itself. In this study, we have obtained a higher-resolution crystal structure of the enzyme, which shows that the ion bound is, in fact, zinc. Analysis of the structure of the four sites, one per monomer, and quantum chemical calculations of models of the site in the presence of different divalent metal ions show an intrinsic preference for zinc, but also significant flexibility of the site so that binding of other ions can eventually occur. Proteins 2014. (c) 2013 Wiley Periodicals, Inc. Characterization of the divalent metal binding site of bacterial polysaccharide deacetylase using crystallography and quantum chemical calculations.,Munan Shaik M, Bhattacharjee N, Bhattacharjee A, Field MJ, Zanotti G Proteins. 2013 Dec 17. doi: 10.1002/prot.24497. PMID:24346839[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
| ||||||||||||||||||||
