Erker J C, Simons J N, Muerhoff A S, Leary T P, Chalmers M L, Desai S M, Mushahwar I K
Virus Discovery Group, Experimental Biology Research, Abbott Laboratories, North Chicago, IL 60064, USA.
J Gen Virol. 1996 Nov;77 ( Pt 11):2713-20. doi: 10.1099/0022-1317-77-11-2713.
Recently, the isolation of a novel virus, GB virus C (GBV-C), associated with cryptogenic hepatitis has been reported. Following the molecular cloning of this virus genome, it became apparent that the genomic sequence did not encode a protein resembling a nucleocapsid or core-like protein similar to those observed in other flaviviruses, pestiviruses, hepatitis C virus (HCV) and GB virus B. Similar findings were subsequently observed in the cloning of two viral genomes representing isolates of GBV-C, namely hepatitis G virus (HGV). To verify the presence or absence of a viral nucleocapsid protein, identify conserved protein motifs and determine the overall genomic variability, an additional virus isolate has been characterized. Here we report the full-length genomic sequence of GBV-C(EA), isolated from an East African suffering from acute non-A-E hepatitis. GBV-C(EA) was compared with the prototype West African isolate (GBV-C) and the two HGV isolates from the United States. The analyses demonstrate several characteristics of these novel viruses. (1) The degree of variability within the 5' nontranslated region (NTR) approximates that observed between HCV isolates. (2) The nucleotide sequence of the coding region and the 3' NTR is highly conserved between these isolates, in contrast to the extensive variability observed between HCV isolates from distinct geographical locations. (3) There is a high degree of amino acid conservation across the precursor polyproteins of these isolates; most striking is the lack of 'hypervariable' regions within the envelope proteins. (4) There appears to be no nucleocapsid protein near the amino terminus of the GBV-C/HGV polyproteins.
最近，有报道称分离出一种与不明原因肝炎相关的新型病毒，即GB病毒C（GBV-C）。在对该病毒基因组进行分子克隆后，发现其基因组序列并未编码出一种类似于在其他黄病毒、瘟病毒、丙型肝炎病毒（HCV）和GB病毒B中观察到的核衣壳或核心样蛋白的蛋白质。随后在克隆代表GBV-C分离株的两个病毒基因组（即庚型肝炎病毒（HGV））时也观察到了类似的结果。为了验证病毒核衣壳蛋白的存在与否、确定保守的蛋白质基序并测定总体基因组变异性，对另外一株病毒分离株进行了特征分析。在此，我们报告从一名患有急性非甲非戊型肝炎的东非患者体内分离出的GBV-C（EA）的全长基因组序列。将GBV-C（EA）与原型西非分离株（GBV-C）以及来自美国的两株HGV分离株进行了比较。分析揭示了这些新型病毒的几个特征。（1）5'非翻译区（NTR）内的变异程度与HCV分离株之间观察到的变异程度相近。（2）与来自不同地理位置的HCV分离株之间观察到的广泛变异相反，这些分离株之间编码区和3' NTR的核苷酸序列高度保守。（3）这些分离株的前体多蛋白之间存在高度的氨基酸保守性；最显著的是包膜蛋白内缺乏“高变区”。（4）在GBV-C/HGV多蛋白的氨基末端附近似乎不存在核衣壳蛋白。
