MOLECULAR STRUCTURE OF HAV--GENOMIC SEQUENCE AND ORGANIZATION

甲型肝炎病毒野毒株HM-175的全核苷酸序列为 下定决心。基因组全长7478个核苷酸，后面跟着一个多聚A Tail，编码2227个氨基酸的多蛋白。以氨基为基础 与其他小核糖核酸病毒的酸同源性，推测的裂解位点 多蛋白已被鉴定出来。VP1、VP2和VP2的分子量 根据序列数据预测的VP3与由下列公式确定的VP3一致 生物物理学方法。蛋白质2C和3D与其他蛋白质同源性最高 小核糖核酸病毒。甲型肝炎病毒与蛋白质3C上推测的活性酶位点相同 和3D与其他小核糖核酸病毒。野生型HM-175与A株的比较 细胞培养适应株(Najarian，PNAS 1985)显示624个核小体 差异(91.7%)，但只有34个氨基酸差异(98.5%) 身份)。 野生型HV HM-175已在非洲绿原色中传代30次 猴肾(AGMK)细胞。由此产生的病毒P30 HM-175被减毒 对于黑猩猩来说。已从后一种病毒中制备了cdna克隆并 我们目前正在刻画克隆人的特征。序列的比较 携带野生型HM-175甲型肝炎病毒的P30应有助于定位基因组区域 负责适应细胞培养和衰减。

The complete nucleotide sequence of wild-type HAV strain HM-175 was determined. The genome is 7478 nucleotides long, followed by a poly A tail, and encodes a polyprotein of 2227 amino acids. On the basis of amino acid homology with other picornaviruses, putative cleavage sites for the polyprotein have been identified. The molecular weights of VP1, VP2, and VP3 predicated from the sequence data agree with those determined by biophysical methods. Proteins 2C and 3D are most homologous with other picornaviruses. HAV shares the putative active enzyme sites on proteins 3C and 3D with other picornaviruses. Comparison of wild-type HM-175 with a cell culture adapted strain (Najarian, PNAS 1985) shows 624 necloetide differences (91.7% identity), but only 34 amino acid differences (98.5% identity). Wild-type HAV HM-175 has been passaged 30 times in primary African green monkey kidney (AGMK) cells. The resultant virus, P30 HM-175, is attenuated for chimpanzees. cDNA clones have been prepared from this latter virus and we are currently characterizing the clones. Comparison of the sequence of P30 with wild-type HM-175 HAV should help to locate regions of the genome responsible for adaptation to cell culture and attenuation.