斜纹夜蛾核多角体病毒DNA XbaI 4.0 kb片段锌指蛋白基因及重复序列分析

Nucleotide Sequence of Spodoptera litura Nucleopolyhedrovirus DNA Xba I 4.0 kb Containing the Zinc Finger Protein Gene and Repetitive Sequence Regions

测定了斜纹夜蛾核多角体病毒 (Spodopteralituranucleopolyhedrovirus,SpltNPV)中山大学分离株基因组DNAXbaI4.0kb片段全序列 ,该片段包括一个锌指蛋白基因及三个区域的DNA重复序列 (SR1、SR2、SR3)。该锌指蛋白基因读码框为 2 196个核苷酸 ,编码 731个氨基酸的蛋白质 ,分子量为 83 .0 9kD ,该蛋白的等电点为 4.6 1。在其 5′非编码区内有一个杆状病毒早期启动子基序GAGT及一个TATA盒 ,在其终止密码的下游有 5个真核生物转录mRNA时poly(A)加尾信号AATAAA。在 2 2 3～ 2 41氨基酸残基之间有一个锌指蛋白基序 ,这一基序属于锌指蛋白基序中的C3HC4类 ,即环指 (Ringfinger)类基序。在 32 3～ 340氨基酸残基区域为一个核定位信号。该蛋白可能为一个高度折叠的蛋白质。在该片段中存在三个DNA重复序列区域 (SR1、SR2、SR3) ,其中SR1与SR3区域存在更大量的重复序列 ,SR1区域其中的一个重复序列长达 41bp ,SR1、SR3重复序列区域可能作为该病毒转录的增强子 ,或者作为DNA复制的起始点。

The complete nucleotide sequence of Spodoptera litura nucleopolyhedrovirus(SpltNPV)DNA Xba I 4.0 kb has been determined.It contains a zinc finger protein gene and three repetitive sequence regions.The open reading frame of this zinc finger gene is 2 196 bp long,encoding a putative protein of 731 amino acids with molecular weight of 83.09 kD and isoelectric point of 4.61.The 5′noncoding region of this gene has one baculovirus early promoter motif(GAGT)and one TATA box .Five polyadenylation signals,AATAAA,are found in the downstream of the translation stop codon.A ring finger motif which is a C3HC4 type of zinc finger protein motif and a nuclear localization signal are present at the amino acid residues 232～241 and 323～340 respectively.This protein is probably highly curled.Three repetitive sequence regions(SR1,SR2,SR3)are present in this fragment.SR1 and SR3 contain numerous repetitive sequences,and one of these in SR1 is 41bp long.SR1 and SR3 possibly act as the transcriptional enhancers or origins of replication.