Gorziglia M, Green K, Nishikawa K, Taniguchi K, Jones R, Kapikian A Z, Chanock R M
Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland 20892.
J Virol. 1988 Aug;62(8):2978-84. doi: 10.1128/JVI.62.8.2978-2984.1988.
The complete nucleotide sequence of the fourth gene of symptomatic (Wa, DS-1, P, and VA70) and asymptomatic (M37, 1076, McN13, and ST3) rotaviruses of serotype 1, 2, 3, or 4 was determined by the dideoxy chain termination method. In each strain, the fourth gene, which encodes the outer capsid protein VP3, is 2,359 base pairs in length and has 5'- and 3'-noncoding regions of 9 and 25 nucleotides, respectively. The gene has a single long open reading frame of 2,325 base pairs that is capable of coding for a protein of 775 amino acids. A total of 14 N-terminal and 12 C-terminal amino acids are completely conserved or almost completely conserved, respectively, among nine human rotavirus VP3 genes that have been sequenced. In addition, there is conservation of arginine at the two trypsin cleavage sites as well as conservation of clusters of amino acids in different regions of the two VP3 cleavage products, VP8 and VP5. Three distinct forms of VP3 were identified among the nine human rotavirus strains analyzed. Three symptomatic rotaviruses (serotypes 1, 3, and 4) possess highly related VP3 genes (92.2 to 97% nucleotide identity). Two symptomatic serotype 2 rotaviruses possess VP3 genes which are even more closely related to each other (98.6% nucleotide identity) and only moderately related to the aforementioned VP3 genes of serotypes 1, 3, and 4 (87.4 to 88.2% nucleotide identity). The four asymptomatic rotaviruses, which constitute the third group, possess highly related VP3 genes (95.5 to 97.5% nucleotide identity) which are distinct from those of the virulent rotaviruses (73 to 74.8% nucleotide identity). At 91 positions in the protein sequence of VP3, an amino acid is conserved among the asymptomatic rotaviruses, while a different amino acid is conserved among the symptomatic rotaviruses. Notably, five regions are conserved among the symptomatic rotaviruses, while a different set of sequences are conserved among the asymptomatic rotaviruses. It is possible that some or all of these regions of sequence dimorphism may be responsible for the difference in virulence of these two groups of human rotaviruses. There are 13 regions in the VP3 protein sequence which exhibit the greatest variability; the majority of these variable regions are observed between amino acids 106 to 192. These regions may represent potential antigenic sites related to heterotypic rotavirus neutralization.
采用双脱氧链终止法测定了1、2、3或4型有症状（Wa、DS - 1、P和VA70）及无症状（M37、1076、McN13和ST3）轮状病毒第四基因的完整核苷酸序列。在每个毒株中，编码外衣壳蛋白VP3的第四基因长度为2359个碱基对，5'和3'非编码区分别为9个和25个核苷酸。该基因有一个2325个碱基对的单一长开放阅读框，能够编码一个775个氨基酸的蛋白质。在已测序的9个人轮状病毒VP3基因中，共有14个N端氨基酸和12个C端氨基酸分别完全保守或几乎完全保守。此外，两个胰蛋白酶切割位点的精氨酸保守，VP3切割产物VP8和VP5不同区域的氨基酸簇也保守。在所分析的9个人轮状病毒毒株中鉴定出三种不同形式的VP3。三种有症状的轮状病毒（1、3和4型）拥有高度相关的VP3基因（核苷酸同一性为92.2%至97%）。两种有症状的2型轮状病毒拥有彼此更为密切相关的VP3基因（核苷酸同一性为98.6%），与上述1、3和4型的VP3基因只有中度相关性（核苷酸同一性为87.4%至88.2%）。构成第三组的四种无症状轮状病毒拥有高度相关的VP3基因（核苷酸同一性为95.5%至97.5%），与致病轮状病毒的VP3基因不同（核苷酸同一性为73%至74.8%）。在VP3蛋白序列的91个位置，无症状轮状病毒中有一个氨基酸保守，而有症状轮状病毒中有另一个不同的氨基酸保守。值得注意的是，有症状轮状病毒中有五个区域保守，而无症状轮状病毒中有另一组不同的序列保守。这些序列二态性区域中的一些或全部可能是这两组人轮状病毒毒力差异的原因。VP3蛋白序列中有13个区域表现出最大变异性；这些可变区域大多数出现在第106至192位氨基酸之间。这些区域可能代表与异型轮状病毒中和相关的潜在抗原位点。
