title: Structural basis of rotavirus strain preference toward N-acetyl- or N-glycolylneuraminic acid-containing receptors.
abstract: The rotavirus spike protein domain VP8* is essential for recognition of cell surface carbohydrate receptors, notably those incorporating N-acylneuraminic acids (members of the sialic acid family). N-Acetylneuraminic acids occur naturally in both animals and humans, whereas N-glycolylneuraminic acids are acquired only through dietary uptake in normal human tissues. The preference of animal rotaviruses for these natural N-acylneuraminic acids has not been comprehensively established, and detailed structural information regarding the interactions of different rotaviruses with N-glycolylneuraminic acids is lacking. In this study, distinct specificities of VP8* for N-acetyl- and N-glycolylneuraminic acids were revealed using biophysical techniques. VP8* protein from the porcine rotavirus CRW-8 and the bovine rotavirus Nebraska calf diarrhea virus (NCDV) showed a preference for N-glycolyl- over N-acetylneuraminic acids, in contrast to results obtained with rhesus rotavirus (RRV). Crystallographic structures of VP8* from CRW-8 and RRV with bound methyl-N-glycolylneuraminide revealed the atomic details of their interactions. We examined the influence of amino acid type at position 157, which is proximal to the ligand's N-acetyl or N-glycolyl moiety and can mutate upon cell culture adaptation. A structure-based hypothesis derived from these results could account for rotavirus discrimination between the N-acylneuraminic acid forms. Infectivity blockade experiments demonstrated that the determined carbohydrate specificities of these VP8* domains directly correlate with those of the corresponding infectious virus. This includes an association between CRW-8 adaption to cell culture, decreased competition by N-glycolylneuraminic acid for CRW-8 infectivity, and a Pro157-to-Ser157 mutation in VP8* that reduces binding affinity for N-glycolylneuraminic acid.
authors.affiliation: Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia.
authors.forename: Xing
authors.initials: X
authors.lastname: Yu
authors.forename: Vi T
authors.initials: VT
authors.lastname: Dang
authors.forename: Fiona E
authors.initials: FE
authors.lastname: Fleming
authors.forename: Mark
authors.initials: M
authors.lastname: von Itzstein
authors.forename: Barbara S
authors.initials: BS
authors.lastname: Coulson
authors.forename: Helen
authors.initials: H
authors.lastname: Blanchard
mesh_terms: D001483:Base Sequence; D002151:Calorimetry; D018360:Crystallography, X-Ray; D017931:DNA Primers; D005434:Flow Cytometry; D008958:Models, Molecular; D009438:Neuraminic Acids / Q000737:chemistry / Q000378:metabolism*; D019906:Nuclear Magnetic Resonance, Biomolecular; D011991:Receptors, Virus / Q000378:metabolism*; D012401:Rotavirus / Q000502:physiology*; D012794:Sialic Acids / Q000737:chemistry / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D009438:Neuraminic Acids; D011991:Receptors, Virus; D012794:Sialic Acids; C032592:N-glycolylneuraminic acid