title: Sequencing of prototype viruses in the Venezuelan equine encephalitis antigenic complex.
abstract: The 5' nontranslated region (5'NTR) and nonstructural region nucleotide sequences of nine enzootic Venezuelan equine encephalitis (VEE) virus strains were determined, thus completing the genomic RNA sequences of all prototype strains. The full-length genomes, representing VEE virus antigenic subtypes I-VI, range in size from 11.3 to 11.5 kilobases, with 48-53% overall G+C contents. Size disparities result from subtype-related differences in the number and length of direct repeats in the C-terminal nonstructural protein 3 (nsP3) domain coding sequence and the 3'NTR, while G+C content disparities are attributable to strain-specific variations in base composition at the wobble position of the polyprotein codons. Highly-conserved protein components and one nonconserved protein domain constitute the VEE virus replicase polyproteins. Approximately 80% of deduced nsP1 and nsP4 amino acid residues are invariant, compared to less than 20% of C-terminal nsP3 domain residues. In two enzootic strains, C-terminal nsP3 domain sequences degenerate into little more than repetitive serine-rich blocks. Nonstructural region sequence information drawn from a cross-section of VEE virus subtypes clarifies features of alphavirus conserved sequence elements and proteinase recognition signals. As well, whole-genome comparative analysis supports the reclassification of VEE subtype-variety IF and subtype II viruses.
authors.affiliation: Arbovirus Diseases Branch, Division of Vector-Borne Infectious Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, U.S. Department of Health and Human Services, Fort Collins, CO 80522, USA. jdmeissner@usa.net
authors.forename: J D
authors.initials: JD
authors.lastname: Meissner
authors.forename: C Y
authors.initials: CY
authors.lastname: Huang
authors.forename: M
authors.initials: M
authors.lastname: Pfeffer
authors.forename: R M
authors.initials: RM
authors.lastname: Kinney
mesh_terms: D020121:5' Untranslated Regions / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D000956:Antigens, Viral / Q000737:chemistry / Q000235:genetics*; D001483:Base Sequence; D017124:Conserved Sequence; D004666:Encephalitis Virus, Venezuelan Equine / Q000235:genetics*; D018397:Equidae; D014644:Genetic Variation; D016679:Genome, Viral; D006736:Horses; D008969:Molecular Sequence Data; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics
chemical_list: D020121:5' Untranslated Regions; D000956:Antigens, Viral; D012367:RNA, Viral; D014764:Viral Proteins