title: The selection pressure analysis of classical swine fever virus envelope protein genes Erns and E2.
abstract: Classical swine fever virus, one member of the family Flaviviridae, is the pathogen of CSF, an economically important and highly contagious disease of pigs. Knowledge of virus genes under positive selection pressure can help identify molecular determinants of virulence or pathogenesis without prior knowledge of the mechanisms governing virulence and pathogenesis and clarify the driving force of classical swine fever virus evolution. The positive selection pressure acting on envelope protein genes E(rns), E1 and E2 of classical swine fever virus were assessed and a site-by-site analysis of the d(N)/d(S) ratio was performed, to identify specific codons undergoing diversifying positive selection. Whilst no significant evidence for positive selection was observed in E1, four positively selected sites (208 in E(rns) and 72, 75, and 200 in E2) were identified. The positively selected site (208) of E(rns) corresponds to one of the amino acid substitutions (Ser to Arg) found in an HS-binding CSFV variant. The mutant at the positively selected site (75) is located within an O-glycosylation motif and altered the predicted glycosylation pattern. In addition, Thr at the positively selective site 200 are directly involved with mAb WH308 with which CS vaccine strain does not react, unlike most of the virulent CSFV strains.
authors.affiliation: State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
authors.forename: Fangqiang
authors.initials: F
authors.lastname: Tang
authors.forename: Zishu
authors.initials: Z
authors.lastname: Pan
authors.forename: Chuyu
authors.initials: C
authors.lastname: Zhang
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000914:Antibodies, Viral / Q000276:immunology; D006692:Classical Swine Fever Virus / Q000235:genetics*; D019295:Computational Biology; D019143:Evolution, Molecular; D006031:Glycosylation; D008562:Membrane Glycoproteins / Q000235:genetics*; D020125:Mutation, Missense; D012641:Selection, Genetic; D014759:Viral Envelope Proteins / Q000235:genetics*; D015678:Viral Structural Proteins / Q000235:genetics*
chemical_list: D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; C466501:E(rns) protein, classic swine fever virus; D008562:Membrane Glycoproteins; D014759:Viral Envelope Proteins; D015678:Viral Structural Proteins; C087086:glycoprotein E2, classical swine fever virus; C107842:protein E1, Classical swine fever virus