Yildiz Esra, Oztan Asli, Sar Funda, Pinarbasi Ergun, Cetin-Atalay Rengul, Akkiz Hikmet, Ozturk Mehmet
Department of Molecular Biology and Genetics and BilGen Genetics and Biotechnology, Research and Development Center, Bilkent University, Ankara, Turkey,
Virus Genes. 2002 Oct;25(2):169-77. doi: 10.1023/a:1020161818764.
Based on direct sequencing information from 5'UTR and NS5B regions, we identified subtype lb as a predominant hepatitis C virus genome in Turkey, which affected more than 91% of 79 patients studied. Next, the full genome sequence of a Turkish lb isolate was obtained by the cloning of polypeptide-encoding region into 7 overlapping fragments. Turkish 1b isolate, which was named HCV-TR1, comprises 9361 nucleotides, including 306 nucleotides of 5'UTR, a single long open reading frame of 9033 nucleotides, and 22 nucleotides of 3'UTR. When compared to HCV lb polypeptide sequences available at GenBank, the predicted polypeptide displayed a total of 36 amino acid substitutions, of which 16 was specific for HCV-TR1 isolate. Despite these changes, major structural and functional motifs of HCV proteins were maintained in HCV-TR1. In contrast, HCV-TR1 displayed amino acid substitutions in 6 out of 9 major cytotoxic T-cell epitopes. These data suggest that HCV-TR1 encodes functionally intact viral proteins, but it also encodes altered viral epitopes, which may affect host immune-response.
基于来自5'非翻译区（UTR）和NS5B区域的直接测序信息，我们确定1b亚型是土耳其丙型肝炎病毒（HCV）的主要基因组类型，在79名研究对象中，该亚型感染率超过91%。接下来，通过将多肽编码区克隆为7个重叠片段，获得了一株土耳其1b亚型分离株的全基因组序列。这株名为HCV-TR1的土耳其1b亚型分离株包含9361个核苷酸，其中5'UTR有306个核苷酸，一个9033个核苷酸的单一长开放阅读框，以及3'UTR的22个核苷酸。与GenBank中现有的HCV 1b亚型多肽序列相比，预测的多肽共有36个氨基酸替换，其中16个是HCV-TR1分离株特有的。尽管有这些变化，但HCV-TR1中HCV蛋白的主要结构和功能基序得以保留。相比之下，HCV-TR1在9个主要细胞毒性T细胞表位中的6个中显示出氨基酸替换。这些数据表明，HCV-TR1编码功能完整的病毒蛋白，但也编码改变的病毒表位，这可能会影响宿主免疫反应。
