家蚕核型多角体病毒ORF 75基因的生物信息学分析

通过对家蚕核型多角体病毒(Bombyx mori,nucleopolyhedrovirus:BmNPV)ORF 75基因核苷酸序列进行生物信息学分析,BmNPVORF 75基因位于病毒基因组70 485 bp和71 264 bp之间,编码259个氨基酸残基的多肽,预测分子相对质量为30.8 kDa,等电点为7.67,分子式为C1409H2157N351O390S19;蛋白在大肠杆菌内的半衰期大于10 h;酸性氨基酸(Asp Glu)占10.5%,碱性氨基酸(Arg Lys)占10.8%;蛋白的不稳定指数为42.67,是不稳定蛋白.利用Prosite数据库扫描,查到4类9个蛋白修饰位点.通过Blast搜索氨基酸同源序列发现,BmNPVORF 75同源蛋白存在于所有测序的鳞翅目昆虫杆状病毒中,不存在于其他非鳞翅目昆虫杆状病毒中.同源序列比对结果,BmNPVORF75蛋白的氨基酸序列与苜蓿银纹夜蛾核型多角体病毒(Autographa californica MNPV)ORF92之间的同源性达到100%,应为相同基因.依照BmNPVORF75同源基因序列相似性,对13种昆虫杆状病毒进行进化树构建分析,其中,BmNPVORF75与薄荷灰夜蛾多粒包埋型核型多角体病毒(Rachiplusia ouMN-PV)ORF89基因进化距离很近,同源性较高.

Bioinformatic Analysis of ORF 75 Gene of Bombyx mori nucleopolyhedrovirus

By bioinformatic analysis of BmNPV ORF 75 gene sequence,Bm 75 gene is located between 70 485 bp and 71 264 bp in the genome of BmNPV,which encoded 259 amino acid residues.The estimated relative molecular weight is 30.8 kDa.Theoretical pI is 7.67.Structural formula is C1409H2157N351O390S19.Its half life was estimated to be beyond 10 hours in E.coli.Total ratio of negatively charged residues(Asp Glu) is 10.5%, total ratio of positively charged residues(Arg Lys) is 10.8%,the protein instability index is deduced to be 42.67 and the protein is unstable.By scaning Prosite data,we found 4 kinds of 9 proteins modified sites.The Blast results indicate BmNPV ORF 75 protein only exits in Lepidoptera Baculovirus.The phylogenetic tree showed the amino acid of BmNPV ORF 75 and AcORF 92 are completely identical, up to 100% homology,they would be the same gene.By phylogenetic analysis of 13 insect baculovirus,the result shows that the gene evolutionary distance of BmNPV ORF 75 and RoMNPV ORF 89 is very close.These two genes share a relatively higher similarity.