2株微孢子虫热激蛋白Hsp70的ORF研究

Study on the Open Reading Frame(ORF)of Two Microsporidia Strains Hsp70

为探讨微孢子虫的起源、分类地位及亲缘关系,在系统发育分析的基础上,对家蚕微孢子虫(Nosema.bombycis)和柞蚕微孢子虫(N.antheraeae)Hsp70基因的ORF序列进行克隆、测序,同时将2种微孢子虫的Hsp70基因的ORF序列翻译成氨基酸序列,利用Expasy蛋白质数据库的分析工具和DNAstar软件对其功能进行理论分析和预测。结果表明:家蚕微孢子虫和柞蚕微孢子虫的Hsp70氨基酸序列在N端均有一个高度保守的基序GIDLGTT,另外还有被作为线粒体Hsp70标志的2个保守的基序;氨基酸序列相似性比较结果发现,家蚕微孢子虫广东株Hsp70的蛋白氨基酸序列和家蚕微孢子虫日本株的相似性最近,约为96%。系统发育分析发现,微粒子属和变形虫属有较近的亲缘关系。功能预测表明,2种微孢子虫在信号肽剪切位点、跨膜结构域及糖基化位点、二级结构、亲水性、柔韧性等方面均存在异同。

In order to explore the origin,taxonomic status and genetic relationship,based on the analysis of phylogeny,the authors cloned and sequenced the Hsp70 gene of N.bombycis and N.antheraeae.Meantime,theoretical analysis and predetermination of the antigenicity function of amino acid translated from nucleotide sequence were conducted by using tools in Expasy database and DNAstar software.The results showed that there was a highly conserved motif GIDLGTT on N-termianl of these two microsporidia Hsp70 gene.And also there were two conserved motif regarded as a marker of mitochondria Hsp70.Amino acids homology blast displayed a 96% similarity with N.bombycis japan.Phylogenetic analysis results showed that Nosema had close relative to Varimorpha.Function prediction showed that,there were similarities and differences in splice sites of signal peptide,transmembrane domain,glycosylation sites,secondary structure,hydrophily,and flexibility and so on.