5ajn
From Proteopedia
Crystal structure of the inactive form of GalNAc-T2 in complex with the glycopeptide MUC5AC-Cys13
Structural highlights
FunctionMUC5A_HUMAN Gel-forming glycoprotein of gastric and respiratory tract epithelia that protects the mucosa from infection and chemical damage by binding to inhaled microorganisms and particles that are subsequently removed by the mucociliary system (PubMed:14535999, PubMed:14718370). Interacts with H.pylori in the gastric epithelium, Barrett's esophagus as well as in gastric metaplasia of the duodenum (GMD) (PubMed:14535999).[1] [2] [3] Publication Abstract from PubMedProtein O-glycosylation is controlled by polypeptide GalNAc-transferases (GalNAc-Ts) that uniquely feature both a catalytic and lectin domain. The underlying molecular basis of how the lectin domains of GalNAc-Ts contribute to glycopeptide specificity and catalysis remains unclear. Here we present the first crystal structures of complexes of GalNAc-T2 with glycopeptides that together with enhanced sampling molecular dynamics simulations demonstrate a cooperative mechanism by which the lectin domain enables free acceptor sites binding of glycopeptides into the catalytic domain. Atomic force microscopy and small-angle X-ray scattering experiments further reveal a dynamic conformational landscape of GalNAc-T2 and a prominent role of compact structures that are both required for efficient catalysis. Our model indicates that the activity profile of GalNAc-T2 is dictated by conformational heterogeneity and relies on a flexible linker located between the catalytic and the lectin domains. Our results also shed light on how GalNAc-Ts generate dense decoration of proteins with O-glycans. Dynamic interplay between catalytic and lectin domains of GalNAc-transferases modulates protein O-glycosylation.,Lira-Navarrete E, de Las Rivas M, Companon I, Pallares MC, Kong Y, Iglesias-Fernandez J, Bernardes GJ, Peregrina JM, Rovira C, Bernado P, Bruscolini P, Clausen H, Lostao A, Corzana F, Hurtado-Guerrero R Nat Commun. 2015 May 5;6:6937. doi: 10.1038/ncomms7937. PMID:25939779[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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