SEQUENCE OF THE FOURTH ROTAVIRUS GENE AND ITS ROLE IN VIRULENCE

轮状病毒第四基因的研究 无症状感染的新生儿托儿所表现出明显的保守性 顺序。 类似地，毒性轮状病毒的第四个基因表现出 序列的保守性，但这种保守的序列不同于 无症状菌株 该基因4序列二态性通过 编码VP 8的第四个基因区域的序列分析 蛋白质、下游切割位点和VP 5的N末端。 人类 轮状病毒在其基因组的这一区域中表现出许多相似性， 包括相同的N-末端氨基酸序列， 精氨酸在两个胰蛋白酶切割位点和半胱氨酸的位置 残余物 无症状和强毒株的氨基酸序列比对 人轮状病毒株显示高度同源性（96%或更高） 在无症状病毒（血清型1、2、3和4）中， 无症状菌株和强毒病毒之间的差异要小得多 （68-72%）。 氨基酸序列高度保守（92-97%）， 在3种强毒株（血清型1、3和4）中也观察到。 在 在VP 8的蛋白质序列中的48个位置，切割区和N 在无症状轮状病毒中，VP 5末端的氨基酸是保守的， 而不同的氨基酸在毒性轮状病毒中是保守的。 值得注意的是，这些差异中的三个位于短的6个氨基内。 VP 8和VP 5之间的酸裂解区。 有可能部分或全部 这一序列的二态性可能是负责的差异， 这两组人类轮状病毒之间的毒力。

The fourth gene of rotavirus strains recovered from outbreaks of asymptomatic infection in newborn nurseries exhibits a marked conservation of sequence. Similarly, the fourth gene of virulent rotaviruses exhibits conservation of sequence but this conserved sequence differs from that of the asymptomatic strains. This gene 4 sequence dimorphism was studied by sequence analysis of the region of the fourth gene that codes for the VP8 protein, downstream cleavage sites and the N terminus of VP5. The human rotaviruses exhibit many similarities in this region of their genome, including identical N-terminal amino acid sequences, conservation of arginine at the two trypsin cleavage sites and the position of a cysteine residue. Alignment of amino acid sequences of asymptomatic and virulent human rotavirus strains indicates a high degree of homology (96% or more) among the asymptomatic viruses (serotypes 1, 2, 3 and 4), while homology between asymptomatic strains and virulent viruses is considerably less (68-72%). A high degree of conservation of amino acid sequence (92-97%) is also observed among 3 of the virulent strains (serotypes 1, 3 and 4). At 48 positions in the protein sequence of VP8, the cleavage region and the N terminus of VP5 an amino acid is conserved among asymptomatic rotaviruses, while a different amino acid is conserved among virulent rotaviruses. Notably, three of these differences are located within the short 6 amino acid cleavage region between VP8 and VP5. It is possible that some or all of this sequence dimorphism may be responsible for the difference in virulence between these two groups of human rotaviruses.