大鲵虹彩病毒-LY株主要衣壳蛋白基因克隆和分子特征研究  

Gene Cloning and Molecular Characteristics of Major Capsid Protein from Chinese Giant Salamander(Andrias davidianus) Iridovirus-LY Isolate

作　　者：周小愿[1] 张星朗[1] 韩亚慧 贾秋红[1] 高宏伟[1] 

机构地区：[1]中国水产科学院黄河水产研究所,西安710086

出　　处：《中国农学通报》2015年第5期45-54,共10页Chinese Agricultural Science Bulletin

基　　金：陕西省科学技术计划项目"养殖大鲵病毒性疾病控制关键技术研究与应用示范"(2012k01-18);陕西省科学技术计划项目(2014k20-02);陕西水利科技计划项目(2012-04)

摘　　要：为明确大鲵虹彩病毒-LY株主要衣壳蛋白（mcp）基因分子特征和中国不同CGSIV毒株mcp基因变异及病毒的系统进化关系。克隆了CGSIV-LY株mcp基因,并运用生物信息学软件对获得的基因信息进行了分析。结果表明CGSIV-LY株mcp基因全长1392 bp,可编码463个氨基酸。预测蛋白质分子量为50.03 ku,理论等电点是5.75,为亲水性可溶蛋白。CGSIV-LY株mcp不含有信号肽;没有跨膜区存在;抗原表位预测显示抗原性良好;结构预测显示,存在8个潜在的N-糖基化位点,存在17个潜在的O-糖基化位点和20个潜在的磷酸化位点。CGSIV-LY株mcp二级结构中无β-折叠,无规则卷曲占57.66%,延伸链占31.11%,α-螺旋占11.23%,主要以延伸链和无规则卷曲为主。氨基酸序列包含3个结构域：氨基酸N末端,氨基酸C末端和capsid_NCLDV保守区结构域,并在氨基酸序列的第414~436区存在一个低复杂度域。氨基酸序列多重比对和基于mcp氨基酸序列构建的蛙病毒属成员系统进化树分析结果显示,包括CGSIV-LY株在内的中国出现的不同CGSIV毒株之间mcp基因差异很小,为平行进化关系,共同聚为蛙病毒属成员独立的一支。中国出现的不同CGSIV毒株mcp基因应具有基本一致的分子结构和特征。The objectives of this study were to analyze the molecular characteristics and structure of majorcapsid protein（mcp） from Chinese giant salamander iridovirus（CGSIV）-LY isolate,genetic variation of mcp from different CGSIV isolates in China and the evolution of CGSIV.The complete DNA of mcp from CGSIV-LY strain was cloned through PCR amplification and then the molecular characteristics of mcp were studied bymeans of bioinformics software,and phylogenetic tree was constructed by genetic distances.The length of the mcp gene,encoding 463 aa,was 1392 bp,The molecular weight was 50.03 ku and the isoelectric was 5.75.Theprotein is hydrophobic with no signal peptide and transmembrane regions.The antigenicity of the protein wasgood.According to the protein structure prediction,there were 8 N-glycosylation sites,17 O-glycosylation sitesand 20 phosphorylation sites.The secondary structure of this protein consisted primarily of a 11.23% alphahelix,with a 31.11% strand chain and random coil 57.66% without β folding,which contains three domains：theamino acid N terminal,the amino acid C terminal,capsid NCLDV conserved domain including a low complexity region.The results of homologous comparison of amino acid sequences and evolutionary treeindicated that there was little genetic variation among mcps from different CGSIV isolates in China,and thatthese isolates were clustered as an independent branch in Ranavirus with parallel relationship.The protein ofmcp from different isolates of CGSIV with little genetic variations should possess consistent molecularcharacteristics and structure.

关 键 词：大鲵 虹彩病毒 主要衣壳蛋白 克隆 结构预测 

分 类 号：Q941[生物学—植物学]