斜纹夜蛾核多角体病毒几丁质酶基因上游4.0kb的序列分析

Sequence Analysis of 4.0 kb Region Upstream of the Chitinase Gene of Spodoptera litura Nucleopolyhedrovirus

本文报道了斜纹夜蛾核多角体病毒几丁质酶基因 (chiA)上游约 4.0kb范围内的序列 ,它包括了六个读码框(ORF1～ 6 ) ,其长度分别为 15 6bp、2 97bp、5 40bp、36 9bp、12 81bp和 2 2 8bp ,可编码的氨基酸长度分别为 5 1、98、179、12 2、42 6和 75个 ,分子量分别为 6 .15kD、11.46kD、2 1.70kD、14.6 9kD、47.5 9kD和 9.0 9kD。在ORF1、ORF2、ORF3起始密码前分别有一个、二个及一个杆状病毒早期启动子基序CAGT ;在ORF4、ORF5起始密码前各有一个及二个杆状病毒晚期启动子基序TAAG。在ORF1、ORF4、ORF5终止密码下游有真核生物mRNA转录poly(A)加尾信号。ORF4为AcMNPVORF5 3、BmNPVORF42、OpMNPVORF5 6、LdMNPVORF5 4的同源基因。ORF1、ORF2、ORF6与已知的杆状病毒基因没有同源性 ,可能为三个新的基因。

The region of about 4.0 kb upstream of Spodoptera litura nucleopolyhedrovirus (SpltNPV) chiA gene was sequenced, in which six open reading frames(ORF1～6) were found. These ORFs are 156, 297, 540, 369, 1281, and 228 nucleotides long, encoding the proteins of 51, 98, 179, 122, 426, and 75 amino acids with the molecular weight of 6.15 kD, 11.46 kD, 21.70 kD, 14.69 kD, 47.59 kD, and 9.09 kD respectively. One early promoter motif CAGT in ORF1 and ORF3, two early promoter motifs CAGT in ORF2, one late promoter motif TAAG in ORF4 and two late promoter motifs TAAG in ORF5 were found in 5′noncoding regions of these ORFs. The polyadenylation signals, AATAAA, are located downstream of the translation stop codon of ORF1, ORF4 and ORF5. ORF4 is the homologous gene of AcMNPV ORF53, BmNPV ORF42, OpMNPV ORF56 and LdMNPV ORF54. Compared with all genes from baculoviruses, ORF1, ORF2 and ORF6 have no homologous genes. It is suggested that ORF1, ORF2 and ORF6 may be three novel baculovirus genes.