绵羊肺炎支原体溶血素TlyC基因的克隆及分子特征分析

摘要

According to the genomic sequence of Mycoplasmao vipneumoniae (MO ) , the hemolysin TlyC gene of MO Xinjiang isolate (MO XJ) was amplified with designed specific primers by PCR ,and then sequenced .The molecular characteristic of TlyC gene and it's encoding protein were analyzed by molecular biology software ,and identities among other isolates of Mycoplasmao vipneumoniae were compared .Phy-logenetic tree was constructed to analyze the relationship among different Mycoplasmas . The results showed that the TlyC gene of MO XJ strain contains 1239 base pairs ,encoding a polypeptide of 412 amino acid residues .The deduced protein had a signal peptide sequence between amino acids 1 and 23 ,containing transmembrane and CBS structure of the domain ,Polypeptide chain is mainly composed of alpha helix . Phylogenetic tree revealed that the sequences of MO had high identities with Hemolysin of Mycoplasma hyopneumoniae 232 ,Hemolysin C Mycoplasma flocculare , and the far distant with other Mycoplasma strains .MO TlyC genes was firstly cloned in this study ,which laid a foundation for understanding biolog-ical functions of TlyC and its role in pathogenicity .%根据 GenBank 报道的绵羊肺炎支原体（MO）基因序列，设计特异性引物，对 MO新疆分离株（MO XJ）溶血素 TlyC 基因进行克隆及测序；并对该基因及其编码蛋白进行分子特征分析，并与其他支原体相应序列进行同源性分析，构建该基因系统进化树。结果表明， TlyC 基因全长为1239 bp ，编码426个氨基酸，其中第1～23位氨基酸残基为信号肽，编码区含有跨膜结构域和 CBS 结构域，二级结构以α-螺旋为主。系统发生分析表明，MO 与猪肺炎支原体232株和絮状支原体的相应序列亲缘关系较近，而与其他种支原体的亲缘关系较远。研究首次克隆了 MO TlyC基因，为了解 MO TlyC生物学功能及其致病中的作用奠定了基础。