Craig R. Pringle

Heptad Repeat Sequences are Located Adjacent to Hydrophobic Regions in Several Types of Virus Fusion Glycoproteins

Extensive regions of heptad repeat units consistent with an alpha-helical coiled coil conformation are located adjacent to hydrophobic, potentially fusion-related regions in the amino acid sequences of paramyxovirus fusion and retrovirus envelope glycoproteins. Similar arrangements of hydrophobic peptides and heptad repeat units exist in coronavirus peplomer proteins and influenza virus haemagglutinins. This suggests that there may be similarities in the structures of these proteins and in the functions of the hydrophobic fusion-related regions during virus entry.

Antigenic structure, evolution and immunobiology of human respiratory syncytial virus attachment (G) protein

IP: 54.70.40.11 On: Fri, 07 Dec 2018 06:42:32 Journal of General Virology (1997), 78, 2411–2418. Printed in Great Britain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Virus Taxonomy – San Diego 1998

The 27th Meeting of the Executive Committee of the International Committee on Taxonomy of Viruses (ICTV) was held at the Scripps Research Institute, San Diego, California, on 7th and 8th March of this year. The principle business was review of new taxonomic proposals submitted by the individual Study Groups of the ICTV. The taxonomic proposals listed below are those that were approved by the Executive Committee of the ICTV. These new proposals, subject to formal ratification by postal ballot of the national membership of the ICTV, will be included in the up-dated Universal Taxonomy of Viruses, which will be published as the 7th Report of the ICTV. The Executive Committee plans to have the 7th Report available for sale at the 11th International Congress of Virology, which will take place in Sydney, Australia, in August 1999. The Executive Committee aims to replace vernacular names by international names throughout the Universal Taxonomy, but in certain taxa the designation “...-like viruses” remains. In some cases this is indicative of rejection by the Executive Committee of an international name proposed by a Study Group, or vice versa. In other cases it represents continuing indecision about the definitive criteria for designation of species. A major change in practice was approved at the San Diego Meeting, which is illustrated in the list of new taxonomic proposals that follows. In future the names of all virus species will be italicised and the initial letter will be capitalised. The names of viruses having the status of tentative species only will not be given in italics, but will have the initial letter capitalised. Transition to italicisation will signal recognition of full species status. The Executive Committee of the ICTV has approved the following new taxonomic proposals: Proposals that were rejected or referred back are not included in the list.

Identification of variable domains of the attachment (G) protein of subgroup A respiratory syncytial viruses.

We have previously classified isolates from a respiratory syncytial (RS) virus epidemic into distinct lineages by restriction mapping and nucleotide sequencing of parts of the nucleocapsid protein and small hydrophobic protein genes, which are areas of the genome not considered to be under immunological pressure. This study has now been extended by the determination of the nucleotide sequences of the attachment (G) protein genes of isolates from each subgroup A lineage. Deduced amino acid identities of the G proteins ranged between 80% and 99%, corresponding closely to the previously determined relatedness of the lineages. The amino acid variability was not evenly distributed; in the extracellular part of the protein there was a sharply defined hypervariable domain which was separated from a more extended variable domain by a highly conserved region. Most nucleotide changes in the variable domains were in the first and second positions of the codon triplets. These results suggest that there may be considerable immunological pressure for change in certain areas of the G protein and this may account for the ability of this virus to reinfect individuals repeatedly. The results presented here reflect the pattern of published data comparing prototype strains of the A and B subgroups.

Respiratory syncytial virus heterogeneity during an epidemic: analysis by limited nucleotide sequencing (SH gene) and restriction mapping (N gene)

The genes encoding the small hydrophobic (SH) proteins of a series of respiratory syncytial (RS) virus strains were amplified using the polymerase chain reaction, cloned and sequenced. Analysis of the SH gene sequences from 12 RS virus strains isolated between 1956 and 1989 confirmed the homogeneity of the two subgroups. A and B, previously defined serologically. Although there is only 76% deduced amino acid sequence identity of SH proteins between subgroups, there was little variation in deduced amino acid sequences within the subgroups; nucleotide homologies within the subgroups ranged between 93% and 99%. Forty-two isolates of RS virus from a single epidemic season (autumn/winter 1989) were also examined to determine their relatedness. For these isolates regions of both the SH and nucleocapsid protein genes of each isolate were amplified and these regions were further analysed by direct nucleotide sequencing or restriction mapping. It was possible to discriminate at least six different lineages (or substrains) of RS virus circulating at the same time and in the same locality.

The universal system of virus taxonomy of the International Committee on Virus Taxonomy (ICTV), including new proposals ratified since publication of the Sixth ICTV Report in 1995

A number of new taxonomic proposals have been considered by the Executive Committee of the International Committee on Virus Taxonomy (ICTV) since publication of its Sixth Report in 1995 [2]. Several of these proposals were ratified subsequently at the Plenary Meeting of the ICTV during the Tenth International Congress of Virology in Jerusalem in August 1996. Others have been ratified by postal ballot of the full membership of the ICTV subsequent to a meeting of the Executive Committee of the ICTV in Strasbourg in May 1997. Table 1 presents the current version of the Universal System of Virus Taxonomy which includes the new taxonomic proposals which have been ratified by the ICTV up to the end of 1997 [1]. This is an abbreviated version of the up-dated taxonomy; it does not extend to the listing of approved virus species, a feature which is expanding rapidly. A major revision of virus taxonomy is being undertaken currently by the individual Study Groups of the ICTV, which is scheduled to be published as the Seventh Report of the ICTV prior to the Eleventh International Congress of Virology in Sydney in 1999. The order of presentation of virus taxa follows that adopted in the Sixth Report. It is based on four criteria:

Synthesis of Bunyavirus-specific Proteins in a Continuous Cell Line (XTC-2) Derived from Xenopus laevis

The XTC-2 cell line, derived from Xenopus laevis, supported the replication of representative viruses from each of the four genera in the family Bunyaviridae. Generally, viral titres were higher in XTC-2 cells than in other susceptible cell lines, and for some viruses plaques were detected earlier in XTC-2 cells. The XTC-2 cell line permitted comparative analyses of bunyavirus-specific protein synthesis. The patterns of synthesis of viral proteins, characteristic of each of the genera, were observed with representative viruses. These studies provided biochemical characterization of two Scottish isolates, which support the inclusion of Clo Mor virus in the Nairovirus genus and St Abbs Head (M349) virus in the Uukuvirus genus.

Molecular epidemiology of respiratory syncytial virus: rapid identification of subgroup A lineages

Methods for the rapid analysis of samples of respiratory syncytial (RS) virus are described using the polymerase chain reaction (PCR) followed by restriction mapping. Isolates (either clinical samples or tissue culture grown virus) can readily be divided into subgroups and then further classified into lineages. These methods enable examination of large numbers of isolates by molecular techniques, thereby facilitating research into the molecular epidemiology of the virus.

Nucleotide sequence of the Bunyamwera virus M RNA segment: Conservation of structural features in the Bunyavirus glycoprotein gene product

The complete nucleotide sequence of the Bunyamwera virus M RNA segment was determined from four overlapping cDNA clones and by primer extension. The RNA segment is 4458 bases in length, and encodes a single gene product in the viral complementary RNA. The predicted protein is 1433 amino acids long (mol wt 162,065), contains four potential glycosylation sites, and is relatively cysteine rich. It is presumed that the three proteins G1, G2, and NSM which have been mapped to the M RNA segment are synthesized as a precursor polyprotein which is subsequently proteolytically cleaved. A putative hydrophobic signal sequence at the amino terminus and a hydrophobic anchor sequence at the carboxy terminus of the predicted protein have been identified, in addition to internal regions of hydrophobicity of unknown function. The nucleotide and amino acid sequences of the Bunyamwera virus M segment have been compared with those of the snowshoe hare virus M segment (Y. Eshita and D. H. L. Bishop, Virology 137, 227-240, 1984). Common features include the overall architecture of the RNAs, single cysteine-rich primary gene products, and conservation of hydrophobic domains in the gene products. When aligned the amino acid sequences are 43% homologous, and 66 of 70 cysteine residues can be matched. The evolutionary significance of these findings is discussed.

Analysis of relatedness of subgroup A respiratory syncytial viruses isolated worldwide

Respiratory syncytial virus strains (subgroup A) isolated from around the world during the period 1988-1991 were analysed to determine their relatedness. Analysis was by restriction mapping and nucleotide sequencing following amplification of selected regions of the virus genome by polymerase chain reaction (PCR). Twenty-three viruses of subgroup A isolated from cities in temperate regions of the Northern and Southern hemispheres and the tropics during the period 1988-1991 fell into distinct groupings closely related to four of the six lineages defined in analysis of recurrent epidemics within the same city (Birmingham, UK) during the same period. These observations confirm that multiple lineages of RS virus co-circulate locally, and show that very similar viruses are present simultaneously in widely separated countries.