The sequence and genomic organization of a GB virus A variant isolated from captive tamarins.
Recently, gene fragments of several novel variants of GB virus A were isolated from the serum of distinct monkey species that had not been experimentally inoculated with an infectious agent. These variants appeared to be species-specific in that sequences isolated within a species were virtually identical, though sequences were strikingly different when compared between each species. In the present study, the nucleotide sequence of one of these variants, GBV-Alab, was extended to near-genome length. Similar to the other GB viruses, GBV-Alab appears to encode a single large polyprotein of 2967 amino acids that is post-translationally cleaved by cellular and viral proteases into the individual viral proteins. The structural proteins are found at the N-terminal end of the polyprotein, while the nonstructural proteins are found at the C teminus. Amino acid sequence comparisons of the large polyprotein demonstrate that GBV-Alab is 74% identical to GBV-A and 48% identical to GBV-C, sharing only marginal identity with GBV-B and HCV-1 at 27%. Examination of the GBV-Alab polyprotein reveals that structural motifs are conserved for a protease, a helicase and a replicase. Phylogenetic analysis of the polyprotein confirms previous results that GBV-Alab is a member of the Flaviviridae, distinct from GBV-B and HCV, though more closely related to GBV-A and GBV-C.
Leary
T P
TP
Virus Discovery Group, Abbott Laboratories, Dept., North Chicago, IL 60064, USA. Thomas.Leary@add.ssw.abbott.com
Desai
S M
SM
Erker
J C
JC
Mushahwar
I K
IK
D000595:Amino Acid Sequence; D000818:Animals; D018067:Flaviviridae / Q000235:genetics*; D016679:Genome, Viral; D006031:Glycosylation; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics; D010802:Phylogeny; D011499:Protein Processing, Post-Translational; D012367:RNA, Viral / Q000097:blood / Q000235:genetics; D012452:Saguinus / Q000821:virology*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D017361:Viral Nonstructural Proteins / Q000235:genetics / Q000378:metabolism; D015678:Viral Structural Proteins / Q000235:genetics / Q000378:metabolism
D012367:RNA, Viral; D017361:Viral Nonstructural Proteins; D015678:Viral Structural Proteins