远源链球菌可能与细胞分裂相关的新基因ftsK的克隆与序列分析  

Cloning and sequence analysis of a putative cell division protein gene ftsK of Streptococcus sobrinus

作　　者：苏凌云[1] 吴补领[1] 李福洋[2] 张文红[2] 范继红[1] 

机构地区：[1]第四军医大学口腔医学院,西安710032 [2]第四军医大学基础部生化与分子生物学教研室

出　　处：《中华微生物学和免疫学杂志》2005年第5期379-382,共4页Chinese Journal of Microbiology and Immunology

基　　金：全军"十五"计划重点课题 (0 1Z0 89) ;第四军医大学科技创新工程资助项目 (CX0 2A0 12 )

摘　　要：目的　克隆并分析远源链球菌(S .sobrinus)可能与细胞分裂相关的新基因ftsK。方法采用“genomewalkingsystem(基因组步移系统)”克隆远源链球菌可能与细胞分裂相关的新基因ftsK ,与GenBank进行同源性分析,并用蛋白质分析软件分析ftsK的氨基酸序列。结果　所克隆的新基因由2 10 0个碱基组成,编码6 99个氨基酸。用GOR4软件对S .sobrinusftsK的二级结构预测,显示其主要由α螺旋和无规卷曲组成,另有小部分伸展线,但无β折叠,在其N末端有一跨膜区。对氨基酸序列进行保守区分析,氨基酸335～5 30序列具有ftsK SpoⅢE保守序列,同源性分析,除N末端2 2 6个氨基酸外,其余氨基酸序列与大肠杆菌细胞分裂蛋白FtsK的C末端2 3序列同源,2 17～6 35氨基酸与枯草杆菌SpoⅢE的C末端同源。结论　通过“基因组步移系统”克隆出的新基因可能与远源链球菌细胞分裂蛋白FtsK相关。Objective To clone and analyze a putative cell d ivision protein gene ftsK of Streptococcus sobrinus. Methods A putative cell division protein gene ftsK of Streptococcus s obrinus was cloned by“genome walking system” and PCR amplification. The nucl eic acid sequence and amino acid sequence were compared with GenBank, and the am ino acid sequence was analyzed by protein analysis software. Results The gene was consisted of 2100 bp nucleotides which encode 699 amin o acids. The secondary structure of the putative S.sobrinus ftsK was pre dicted by GOR4 software. The results showed that the secondary structure of the putative S.sobrinus ftsK was composed mostly of alpha helix and random c oil. There were a few extended strands but no beta turns. There was a membrane- spanning region in the N-terminal domain. When the conserved region of amino ac id sequence was analyzed, we found that amino acid sequence 335-530 had the con served region of ftsK/SpoⅢE. Homology analysis demonstrated that the rest a mino acid sequences were homologous to C-terminal 2/3 sequences of E.coli ftsK, except 226 amino acid sequences of N-terminal domain. Amino acid sequ ences 217-635 were homologous to SpoⅢE gene of B.subtilis. From 1 to 65 am ino acid sequences were homologous to N-terminal domain of SpoⅢE. C onclusion The gene cloned in this experiment was a putative cell div ision protein FtsK of Streptococcus sobrinus.

关 键 词：远源链球菌 细胞分裂 ftsK基因 克隆 序列分析 

分 类 号：R378[医药卫生—病原生物学]