结核分枝杆菌PE＿PGRS47蛋白的生物信息学分析

Bioinformatic analysis of the PE＿PGRS47 protein from Mycobacterium tuberculosis

目的获取结核分枝杆菌(H37Rv)的pe_pgrs47基因序列以及编码蛋白PE_PGRS47的氨基酸序列,对PE_PGRS47蛋白结构以及抗原表位进行预测。方法采用ORF Finger工具对pe_pgrs47基因的开放阅读框进行分析;利用Expasy PortParam,SignalP 4.0Server,SOPMA以及SWISS-MODEL等软件和工具分析PE_PGRS47蛋白的生物信息学特征。结果结核分枝杆菌(H37Rv)的pe_pgrs47基因GC含量较高,为74.8%,预测其有5个开放阅读框;PE_PGRS47蛋白由525个氨基酸构成,pl为4.40,属于稳定、疏水性蛋白,含有两个丝氨酸磷酸化位点;二级结构中无规则卷曲结构所占比例较高,为51.05%,预测含有一个结构域,19个B细胞抗原表位,11个限制性CTL表位和16个辅助性T细胞表位。结论 PE_PGRS47蛋白含有一个保守的结构域,其结构域可能与其抑制细胞自噬的功能密切相关,预测其含有丰富的T、B细胞抗原表位,为研究PE_PGRS47蛋白的功能奠定了基础。

Objective To obtain the sequence of the pe_pgrs47 gene of Mycobacterium tuberculosis and the amino acid sequence of the PE_PGRS47 protein,to analyze the basic features of the pe_pgrs47 gene from M.tuberculosis,and to predict and analyze the structure and epitopes of the PE_PGRS47 protein encoded by the pe_pgrs47 gene. Methods ORF Finger was used to analyze the open reading frame of the pe_pgrs47 gene.The biological features of the PE_PGRS47 protein were predicted and analyzed and using online software such as Expasy PortParam,SignalP 4.0 Server,TMHMM Server v.2.0,SOPMA,BLAST,SWISS-MODEL,ABCpred,SYFPEITHI,and NetMHCIIpan 3.1 Server.Results The pe_pgrs47 gene of M.tuberculosis was 1,578 bp in length and has 5 open reading frames.The longest one is read through and encoded 525 amino acids.The GC content of pe_pgrs47 in M.tuberculosis was 74.8%,which is consistent with the high GC content of M.tuberculosis.The PE_PGRS47 protein consisted of 525 amino acids.Its molecular formula was C1866 H2865 N587 O662 S3.The isoelectric point(PI)of the PE_PGRS47 protein was 4.40,so it is a stable and hydrophobic protein.PE_PGRS47 is predicted to contain two serine phosphorylation sites.Its secondary structure mostly consists of random coils,which account for about 51.05% of the structure.The predicted PE_PGRS47 protein has 19 B-cell epitopes,11 CTL epitopes,and 16 T-cell epitopes. Conclusion The PE_PGRS47 protein of M.tuberculosis has an abundance of T-and B-cell epitopes,it has a conserved structure,and that structure is predicted to be closely related to its function.