Muerhoff A S, Simons J N, Leary T P, Erker J C, Chalmers M L, Pilot-Matias T J, Dawson G J, Desai S M, Mushahwar I K
Virus Discovery Group, Abbott Laboratories, North Chicago, IL 60064-4000, USA.
J Hepatol. 1996 Sep;25(3):379-84. doi: 10.1016/s0168-8278(96)80125-5.
GB virus C is a positive-strand RNA virus that is associated with hepatitis in humans. GB virus C bears some resemblance to hepatitis C virus in its genomic sequence and organization. However, unlike hepatitis C virus, an open reading frame possessing a complete core protein was not identified in the original isolate.
To verify the sequence at the 5'-end of the GB virus C genome, we amplified approximately 600 nucleotides from this region from 35 globally distributed individuals. The nucleotide sequences were translated in all possible reading frames and then examined for conserved motifs indicative of nucleocapsid or core-like peptides.
Forty-two unique GB virus C sequences were obtained from the 35 individuals. The deduced amino acid sequences upstream of the putative E1 gene from each isolate varied in length and composition, such that a conserved core-like sequence was not apparent. No core-like sequences were evident in the other reading frames. There was, however, a single methionine codon held in common among all isolates, although it was located very near the presumed amino-terminus of the putative E1 protein. Further analysis of the sequences for their evolutionary relatedness demonstrated the existence of five GB virus C subtypes that demonstrated a significant correlation with geographic distribution.
GB virus C differs from hepatitis C virus and GB virus B in that it does not encode a nucleocapsid or core protein. The existence of GB virus C subtypes emphasizes the importance of investigating the correlation between infecting subtype and the severity of liver disease and/or responsiveness to treatment of GB virus C-associated hepatitis.
GB病毒C是一种与人类肝炎相关的正链RNA病毒。GB病毒C在基因组序列和结构上与丙型肝炎病毒有一些相似之处。然而，与丙型肝炎病毒不同的是，在最初的分离株中未鉴定出具有完整核心蛋白的开放阅读框。
为了验证GB病毒C基因组5′端的序列，我们从全球分布的35个人中扩增了该区域约600个核苷酸。核苷酸序列以所有可能的阅读框进行翻译，然后检查是否存在指示核衣壳或核心样肽的保守基序。
从35个人中获得了42个独特的GB病毒C序列。每个分离株推定的E1基因上游的推导氨基酸序列在长度和组成上各不相同，因此没有明显的保守核心样序列。在其他阅读框中也没有明显的核心样序列。然而，所有分离株中都有一个共同的甲硫氨酸密码子，尽管它位于推定的E1蛋白假定的氨基末端附近。对这些序列的进化相关性进行进一步分析，发现存在五种GB病毒C亚型，它们与地理分布有显著相关性。
GB病毒C与丙型肝炎病毒和GB病毒B不同，它不编码核衣壳或核心蛋白。GB病毒C亚型的存在强调了研究感染亚型与GB病毒C相关肝炎的肝病严重程度和/或治疗反应之间相关性的重要性。
