The turnover of proteins in normal or pathogenic processes requires hydrolysis of the peptide bond, a reaction catalyzed by the peptidase enzyme superfamily. The concept of peptidase specificity is captured in the universally adopted nomenclature defining subsites (S sites) in the enzyme active site that accommodate specific amino acids of the protein or peptide substrate (P residues). As potential protease substrates, however, proteins are often post-translationally modified, and, as such, peptidases must also contend with these modifications to their substrates. Glycosylation is thought to be the most frequent modification of proteins with an estimated one-half of all proteins in nature bearing covalently linked glycans. Individual glycoproteins can be simple, bearing a single defined glycan, to having heavy modifications with varied glycans. Glycosylation is frequently credited for the increased stability of these glycoproteins, yet these glycoconjugates remain substrates for peptidases. Host-adapted bacteria, both pathogenic and commensal, have developed multimodular enzymatic systems to cope with the complex glycans found in the host environment, such as the highly competitive gut niche. Among these deployed enzymatic arsenals are O-glycopeptidases, which uniquely target proteins with O-linked glycan modification. Here you can see a recent crystal structure of the Amuc_1438 glycopeptidase isolated from Akkermansia muciniphila, an human mucin-degrading intestinal bacterium (PDB code: 8DF2)
#molecularart ... #immolecular ... #glycosylation ... #glycosidase ... #degradation ... #mucin ... #intestine ... #microbiome ... #xray
Structure rendered with @proteinimaging and depicted with @corelphotopaint
#molecularart ... #immolecular ... #glycosylation ... #glycosidase ... #degradation ... #mucin ... #intestine ... #microbiome ... #xray
Structure rendered with @proteinimaging and depicted with @corelphotopaint
