斜纹夜蛾核多角体病毒(SpltNPV)碱性核酸外切酶基因的序列分析  

Cloning and Sequence Analysis of the Alkaline Exonuclease Gene of Spodoptera litura nucleopolyhedrovirus

作　　者：李镇[1] 龙綮新[1] 贺雄雷[1] 郑姬 王珣章[1] 庞义[1] 

机构地区：[1]中山大学生物防治国家重点实验室昆虫学研究所,广东广州510275

出　　处：《农业生物技术学报》2001年第3期233-237,共5页Journal of Agricultural Biotechnology

基　　金：家自然科学基金重点项目(39730030)资助

摘　　要：斜纹夜蛾核多角体病毒碱性核酸外切酶基因（ａｌｋ－ｅｘｏ）定位于其基因组的ＸｂａＩ－Ｉ片段上，克隆并测序确定了ａｌｋ－ｅｘｏ全序列：ＳｐｌｔＮＰＶ碱性核酸外切酶基因的完整的读码框为１２２７个核苷酸，编码一长为４０８个氨基酸的蛋白质，在距起始密码子ＡＴＧ上游　３７位、　８０位各有一个启动子基序ＴＡＴＡ框，在-２８位有杆状病毒晚期基因的启动子基序ＴＡＡＧ，在ＯＲＦ终止区有加尾信号ｐｏｌｙ（Ａ）序列ＡＡＴＡＡＡ。根据核苷酸序列推导的蛋白质的分子量为４７　ｋＤ，等电点为８．９，在２９６～３１２位氨基酸存在有一预期跨膜区，其中心位于３０４位的丙氨酸（ＧＦＹＹＳＦＧＡＬＶＣＶＦＣＭＫ）。ＳｐｌｔＮＰＶ　的ａｌｋ－ｅｘｏ氨基酸序列与其它８种杆状病毒的ａｌｋ－ｅｘｏ同源性在３７％～４３％之间，且与疱疹病毒的　ａｌｋ－ｅｘｏ基因有一定的同源性。通过对８种杆状病毒和疱疹病毒的ａｌｋ－ｅｘｏ序列比较发现了５个保守区。s: Alkaline exonuclease gene of Spodopera litura nucleopolyhedrovirus(SpltNPV),which were cloned and sequenced, was localized in XbaI-I 5.2 kb fragment.The complete open reading frame(ORF)of the gene was 1224 nucleotide long,encoding putative protein of 408 amino acids with 47.3 kD. Sequence analysis further revealed that the 5＇ noncoding region had 2 baculovirus early promoter motif TATA and one late promoter motif TAAG.A polyadenylation signal(AATAAA)was contained in the traslation stop codon.A putative transmembrane helices was present at 296～312 from the N-terminus of the protein. Comparison of the homology with other 7 baculovirus alk-exo genes had been done.SpltNPV alk-exo gene showed 373% amino acid identity to other 7 baculovirus. Three conserved regions were observed based on the alignment of the amino acid sequences of 13 alk-exo genes.

关 键 词：斜纹夜蛾核多角体病毒 碱性核酸外切酶基因 序列分析 

分 类 号：S476.13[农业科学—农业昆虫与害虫防治]