5ej0

The vaccinia virus H3 envelope protein, a major target of neutralizing antibodies, exhibits a glycosyltransferase fold and binds UDP-Glucose

spinqualitylabelsall models 5ej0, resolution 1.90Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 5ej0 is a 1 chain structure with sequence from Vaccinia virus WR. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.9Å Ligands: DHL, EDO, EOH, GOL, MG, MOH, PDO, PG0, POL Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function H3_VACCW Envelope protein that binds to heparan sulfate on the cell surface and might provide virion attachment to target cell. Publication Abstract from PubMed The highly conserved H3 poxvirus protein is a major target of the human antibody response against poxviruses and is likely a key contributor to protection against infection. Here, we present the crystal structure of H3 from vaccinia virus at a 1.9-A resolution. H3 looks like a glycosyltransferase, a family of enzymes that transfer carbohydrate molecules to a variety of acceptor substrates. Like glycosyltransferases, H3 binds UDP-glucose, as shown by saturation transfer difference (STD) nuclear magnetic resonance (NMR) spectroscopy, and this binding requires Mg(2+) Mutation of the glycosyltransferase-like metal ion binding motif in H3 greatly diminished its binding to UDP-glucose. We found by flow cytometry that H3 binds to the surface of human cells but does not bind well to cells that are deficient in surface glycosaminoglycans. STD NMR experiments using a heparin sulfate decasaccharide confirmed that H3 binds heparin sulfate. We propose that a surface of H3 with an excess positive charge may be the binding site for heparin. Heparin binding and glycosyltransferase activity may be involved in the function of H3 in the poxvirus life cycle. IMPORTANCE: Poxviruses are under intense research because of bioterrorism concerns, zoonotic infections, and the side effects of existing smallpox vaccines. The smallpox vaccine using vaccinia virus has been highly successful, but it is still unclear why the vaccine is so effective. Studying the antigens that the immune system recognizes may allow a better understanding of how the vaccine elicits immunity and how improved vaccines can be developed. Poxvirus protein H3 is a major target of the immune system. The H3 crystal structure shows that it has a glycosyltransferase protein fold. We demonstrate that H3 binds the sugar nucleotide UDP-glucose, as do glycosyltransferases. Our experiments also reveal that H3 binds cell surface molecules that are involved in the attachment of poxviruses to cells. These structural and functional studies of H3 will help in designing better vaccines and therapeutics. The Vaccinia Virus H3 Envelope Protein, a Major Target of Neutralizing Antibodies, Exhibits a Glycosyltransferase Fold and Binds UDP-Glucose.,Singh K, Gittis AG, Gitti RK, Ostazeski SA, Su HP, Garboczi DN J Virol. 2016 Apr 29;90(10):5020-30. doi: 10.1128/JVI.02933-15. Print 2016 May, 15. PMID:26937025 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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