2i2s
From Proteopedia
Crystal Structure of the porcine CRW-8 rotavirus VP8* carbohydrate-recognising domain
Structural highlights
Function[VP4_ROTP5] Spike-forming protein that mediates virion attachment to the host epithelial cell receptors and plays a major role in cell penetration, determination of host range restriction and virulence. Rotavirus entry into the host cell probably involves multiple sequential contacts between the outer capsid proteins VP4 and VP7, and the cell receptors. According to the considered strain, VP4 seems to essentially target sialic acid and/or the integrin heterodimer ITGA2/ITGB1 (By similarity). Outer capsid protein VP5*: forms the spike "foot" and "body". Acts as a membrane permeabilization protein that mediates release of viral particles from endosomal compartments into the cytoplasm. In integrin-dependent strains, VP5* targets the integrin heterodimer ITGA2/ITGB1 for cell attachment (By similarity). VP8* forms the head of the spikes. It is the viral hemagglutinin and an important target of neutralizing antibodies. In sialic acid-dependent strains, VP8* binds to host cell sialic acid, most probably a ganglioside, providing the initial contact (By similarity). Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedRotavirus infection leads to the death of half a million children annually. The exact specifics of interaction between rotavirus particles and host cells enabling invasion and infection have remained elusive. Host cell oligosaccharides are critical components, and their involvement aids the virus in cell-recognition and attachment, as well as dictation of the remarkable host-specificity that rotaviruses demonstrate. Interaction between the rotavirus spike-protein carbohydrate-binding domain (VP8*) and cell surface oligosaccharides facilitate virus recognition of host cells and attachment. Rotaviruses are considered, controversially, to recognise vastly different carbohydrate structures and either with incorporation of terminal sialic acid or without, as assessed by their ability to infect cells that have been pre-treated with sialidases. Herein, the X-ray crystallographic structures of VP8* from the sialidase insensitive Wa and the sialidase sensitive CRW-8 rotavirus strains that cause debilitating gastroenteritis in human and pig are reported. Striking differences are apparent regarding recognition of the sialic acid derivative methyl alpha-D-N-acetylneuraminide, presenting the first experimental evidence of the inability of the human rotavirus strain to bind this monosaccharide, that correlates with Wa and CRW-8 recognising sialidase-resistant and sialidase-sensitive receptors, respectively. Identified are structural features that provide insight in attainment of substrate specificity exhibited by porcine strains as compared to rhesus rotavirus. Revealed in the CRW-8 VP8* structure is an additional bound ligand that intriguingly, is within a cleft located equivalent to the carbohydrate-binding region of galectins, and is suggestive of a new region for interaction with cell-surface carbohydrates. This novel result and detailed comparison of our representative sialidase-sensitive CRW-8 and insensitive Wa VP8* structures with those reported leads to our hypothesis that this groove is used for binding carbohydrates, and that for the human strains, as for other sialidase-insensitive strains could represent a major oligosaccharide-binding region. Insight into host cell carbohydrate-recognition by human and porcine rotavirus from crystal structures of the virion spike associated carbohydrate-binding domain (VP8*).,Blanchard H, Yu X, Coulson BS, von Itzstein M J Mol Biol. 2007 Apr 6;367(4):1215-26. Epub 2007 Jan 13. PMID:17306299[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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