9株绵羊肺炎支原体内蒙古分离株P113基因克隆及蛋白序列分析

目的]克隆绵羊肺炎支原体内蒙古分离株P113基因，比对、分析不同菌株P113蛋白序列，为研究绵羊肺炎支原体P113蛋白的生物学功能提供参考。方法]设计绵羊肺炎支原体P113基因特异性引物，采用PCR方法扩增9株绵羊肺炎支原体内蒙古分离株的P113基因片段；对获得的9株绵羊肺炎支原体P113基因片段进行测序分析，将DNA序列翻译为氨基酸序列，对不同菌株的P113氨基酸序列进行比对。结果]不同分离株P113基因片段扩增产物大小不同。氨基酸序列分析显示，C末端序列重复区域长度存在差异，以KKAEGA（S）QNQG为主要重复序列单元。不同菌株重复序列单元数量不同，NM01-MO株和CK-MO株的重复序列单元数量最多，为16个；LK-MO株重复序列单元数量最少，为3个；多数菌株之间重复序列单元数量差异较大。结论]绵羊肺炎支原体内蒙古分离株P113氨基酸序列的C末端重复序列单元数量不同，这些不同数量的重复序列影响P113蛋白结构，进而可能影响其生物学功能。

P113 Gene Cloning and Protein Sequence Analysis of 9 Isolates of Mycoplasma ovipneumoniae from Inner Mongolia

Objective] The P113 genes of Mycoplasma ovipneumoniae isolates from Inner Mongolia were cloned, and the P113 protein sequences of various isolates were bioinformatically compared and analyzed, so as to provide references for clarifying the biological function of Mycoplasma ovipneumoniae P113 protein. Method] A set of specific primers were designed to amplify the P113 gene fragments of 9 isolates of Mycoplasma ovipneumoniae from Inner Mongolia. The obtained P113 gene fragments of various isolates were sequenced. The DNA sequences were then translated into amino acid sequences, and the differences in amino acid sequences among various isolates were bioinformatically compared. Result] The PCR amplified products of P113 gene of various isolates varied in size. According to amino acid sequence analysis, the lengths of C-terminal repetitive elements were variable. KKAEGA (S) QNQG was the dominantly observed repetitive element. The number of repetitive elements of the isolates varied. The most repetitive elements were found in the NM01-MO isolate and CK-MO isolate, both of which were 16. The least repetitive elements were found in the LK-MO isolate, which were 3. Most isolates had large differences in the number of repetitive elements. Conclusion] The number of C-terminal repetitive elements in the amino acid sequence of P113 protein of Mycoplasma ovipneumoniae isolates from Inner Mongolia was variable. These repetitive elements had an impact on P113 protein structure, which could then have an impact on its biological activity.