6EJC

Human Xylosyltransferase 1 in complex with peptide QEEEGSGVGQGG

Summary for 6EJC

• Entry DOI: 10.2210/pdb6ejc/pdb
• Descriptor: Xylosyltransferase 1, Protein AMBP, PHOSPHATE ION, ... (5 entities in total)
• Functional Keywords: proteoglycan, glycosyltransferase, golgi, xylosyltransferase, transferase
• Biological source: Homo sapiens (Human); More
• Total number of polymer chains: 2
• Total formula weight: 87373.09

Authors

Briggs, D.C.,Hohenester, E. (deposition date: 2017-09-20, release date: 2018-05-02, Last modification date: 2024-10-23)

Primary citation

Briggs, D.C.,Hohenester, E.
Structural Basis for the Initiation of Glycosaminoglycan Biosynthesis by Human Xylosyltransferase 1.
Structure, 26:801-809.e3, 2018

PubMed Abstract: Proteoglycans (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.

PubMed: 29681470
DOI: 10.1016/j.str.2018.03.014

Experimental method

X-RAY DIFFRACTION (2.057 Å)