中文摘要：

目的：探讨人线粒体转录终止因子2（mitochondrial transcription termination factor 2,MTERF2）的生物学功能。方法：采用生物信息学的方法和工具对人MTERF2的理化性质、跨膜区和信号肽、二级结构功能域、亚细胞定位、蛋白质的功能分类预测、多重序列比对与系统发育树构建、三级结构建模进行系统的分析与研究。结果：人MTERF2蛋白分子量为44.41 kD,等电点为9.15,不具有信号肽和跨膜区。该蛋白定位于细胞线粒体中,N端1-35个氨基酸为前导肽序列,其二级结构主要构成元件为螺旋和无规则卷曲,包含4个MTERF基序。三级结构预测显示该蛋白为球状结构,N端为螺旋结构,C端为无规则卷曲。对该蛋白进行多重序列比对和聚类分析显示,人MTERF2属于直系同源蛋白质,与猩猩MTERF2相似性最高,二者在系统发育树上聚为一类。结论：人MTERF2是一种典型的线粒体DNA结合蛋白质,本研究为进一步探索人MTERF2蛋白的功能提供参考资料和理论依据。

英文摘要：

Objective： To investigate biological function of the human mitochondrial transcription termination factor 2（MTERF2）.Methods： Many bioinformatic methods were used to analyze its physical and chemical properties, hydrophobicity, transmembrane region,signal peptide, secondary structure, functional domain and assortment, multiple alignment, phylogenetic tree and three-dimensional structures. Results： Human MTERF2 belongs to the hydrophilic protein. The calculated molecular mass is 44.41 kD. The theoretical isoelectric point is 9.15. The signal peptide and transmembrane regions can not be found in human MTERF2. It is localized in mitochondria.And its N-terminal 1-35 amino acids are transit peptide. The main compositions of protein secondary structure are-helix and random coil,which contains four MTERF motifs. The prediction of the three-dimensional structure shows a globular structure which have-helix in the N end and random coil in the C end. The results of the multiple alignment and clustering analysis show that human MTERF2 is a kind of orthologous protein belonging to MTERF family. It is the most similar to Pongopygmaeus MTERF2. Both the proteins cluster together.Conclusions： Human MTERF2 is a kind of typical mitochondrial DNA binding protein. Our research can provide some useful information for the further study of the function of human MTERF2.