Muerhoff A S, Leary T P, Simons J N, Pilot-Matias T J, Dawson G J, Erker J C, Chalmers M L, Schlauder G G, Desai S M, Mushahwar I K
Virus Discovery Group, Abbott Laboratories, North Chicago, Illinois 60064, USA.
J Virol. 1995 Sep;69(9):5621-30. doi: 10.1128/JVI.69.9.5621-5630.1995.
The genomes of two positive-strand RNA viruses have recently been cloned from the serum of a GB agent-infected tamarin by using representational difference analysis. The two agent, GB viruses A and B (GBV-A and GBV-B, respectively), have genomes of 9,493 and 9,143 nucleotides, respectively, and single large open reading frames that encode potential polyprotein precursors of 2,972 and 2,864 amino acids, respectively. The genomes of these agents are organized much like those of other pestiviruses and flaviviruses, with genes predicted to encode structural and nonstructural proteins located at the 5' and 3' ends, respectively. Amino acid sequence alignments and subsequent phylogenetic analysis of the RNA-dependent RNA polymerases (RdRps) of GBV-A and GBV-B show that they possess conserved sequence motifs associated with supergroup II RNA polymerases of positive-strand RNA viruses. On the basis of similar analyses, the GBV-A- and GBV-B-encoded helicases show significant identity with the supergroup II helicases of positive-strand RNA viruses. Within the supergroup II RNA polymerases and helicases, GBV-A and GBV-B are most closely related to the hepatitis C virus group. Across their entire open reading frames, the GB agents exhibit 27% amino sequence identity to each other, approximately 28% identity to hepatitis C virus type 1, and approximately 20% identity to either bovine viral diarrhea virus or yellow fever virus. The degree of sequence divergence between GBV-A and GBV-B and other Flaviviridae members demonstrates that the GB agents are representatives of two new genera within the Flaviviridae family.
最近，通过代表性差异分析，从一只感染GB因子的绢毛猴血清中克隆出了两种正链RNA病毒的基因组。这两种因子，即GB病毒A和GB病毒B（分别为GBV-A和GBV-B），基因组分别为9493和9143个核苷酸，并有单一的大开放阅读框，分别编码2972和2864个氨基酸的潜在多蛋白前体。这些因子的基因组结构与其他瘟病毒和黄病毒的基因组非常相似，预测编码结构蛋白和非结构蛋白的基因分别位于5'和3'端。GBV-A和GBV-B的RNA依赖RNA聚合酶（RdRps）的氨基酸序列比对及后续系统发育分析表明，它们具有与正链RNA病毒超群II RNA聚合酶相关的保守序列基序。基于类似分析，GBV-A和GBV-B编码的解旋酶与正链RNA病毒超群II解旋酶具有显著的同源性。在超群II RNA聚合酶和解旋酶中，GBV-A和GBV-B与丙型肝炎病毒组关系最为密切。在整个开放阅读框中，GB因子彼此间氨基酸序列同源性为27%，与1型丙型肝炎病毒的同源性约为28%，与牛病毒性腹泻病毒或黄热病病毒的同源性约为20%。GBV-A和GBV-B与黄病毒科其他成员之间的序列差异程度表明，GB因子是黄病毒科两个新属的代表。
