香蕉束顶病毒基因克隆和序列分析

对香蕉束顶病毒（ＢＢＴＶ）中国分离株ＤＮＡ组份Ｉ（ＤＮＡ－１）、外壳蛋白（ＣＰ）和运转蛋白（ＭＰ）基因进行了克隆和序列分析。ＢＢＴＶＤＮＡ－１含有１１０３个核苷酸，与南太平洋和亚洲分离株分别有８７％－８８％ ９６．９－９８％的核苷酸序列同源性。由ＤＮＡ－１编码的复制酶含有１８６个在酸残基。与南太平洋和亚洲分离株分别有８４．４％－９５．８％和９７．６％、９８．０％的氨基酸序列同源性。外壳蛋白基因由５

SEQUENCE ANALYSIS OF A CHINESE ISOLATE OF BANANA BUNCHY TOP VIRUS

The DNA component 1(DNA 1). coat protein (CP) and putative movement protein (MP) genes of a Chinese isolate of banana bunchy top virus (BBTV) were cloned and sequenced. BBTV DNA 1 was 1103 nucleotides in length, and shared 87% 88% and 96% 98% nucleotide sequence identity with the BBTV DNA 1 of the South Pacific isolates and the Asian isolates, respectively. The replicase encoded by DNA 1 contained 186 amino acid residues, and shared 94.4% 95% and 97.6% 98% amino acid sequence identity with those of the South Pacifc isolates and the Asian isolates, respectively. The CP gene consisted of 510 nucleotides and shared 92.5% nucleotide sequence identity and 98.8% amino acid sequence identity with that of the Australian isolate. The MP gene was composed of 348 nucleotides encoding a protein of 15.6kDa, and shared 90.6% nucleotide sequence identity and 87.9% amino acid sequence identity with that of the Australian isolate. Based on the nucleotide sequences of DNA 1, CP, and MP genes, the comparison of the Chinese BBTV isolate with BBTV isolates from other countries confirm the existence of two distinct groups of BBTV, the South Pacific group and the Asian group. The amino acid sequence of the CP gene, however, is similar between the two BBTV groups.