6eje
From Proteopedia
Human Xylosyltransferase 1 in complex with peptide PAAEGSGEQDFT
Structural highlights
Disease[XYLT1_HUMAN] XYLT1-CDG;Desbuquois syndrome. The disease is caused by mutations affecting the gene represented in this entry. The gene represented in this entry acts as a disease modifier. Function[XYLT1_HUMAN] Catalyzes the first step in biosynthesis of glycosaminoglycan. Transfers D-xylose from UDP-D-xylose to specific serine residues of the core protein. Initial enzyme in the biosynthesis of chondroitin sulfate and dermatan sulfate proteoglycans in fibroblasts and chondrocytes.[1] [SDC1_HUMAN] Cell surface proteoglycan that bears both heparan sulfate and chondroitin sulfate and that links the cytoskeleton to the interstitial matrix. Publication Abstract from PubMedProteoglycans (PGs) are essential components of the animal extracellular matrix and are required for cell adhesion, migration, signaling, and immune function. PGs are composed of a core protein and long glycosaminoglycan (GAG) chains, which often specify PG function. GAG biosynthesis is initiated by peptide O-xylosyltransferases, which transfer xylose onto selected serine residues in the core proteins. We have determined crystal structures of human xylosyltransferase 1 (XT1) in complex with the sugar donor, UDP-xylose, and various acceptor peptides. The structures reveal unique active-site features that, in conjunction with functional experiments, explain the substrate specificity of XT1. A constriction within the peptide binding cleft requires the acceptor serine to be followed by glycine or alanine. The remainder of the cleft can accommodate a wide variety of sequences, but with a general preference for acidic residues. These findings provide a framework for understanding the selectivity of GAG attachment. Structural Basis for the Initiation of Glycosaminoglycan Biosynthesis by Human Xylosyltransferase 1.,Briggs DC, Hohenester E Structure. 2018 Apr 10. pii: S0969-2126(18)30095-9. doi:, 10.1016/j.str.2018.03.014. PMID:29681470[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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