缺失dbpA导致大肠杆菌DNA复制起始延迟  

Absence of dbpA Results in the Delayed Initiation of DNA Replication in Escherichia coli

作　　者：张树军[1,2] 勿呢尔 狄建军[1] 张国文[1] 徐雅楠 ZHANG Shu-jun;Wunier;DI Jian-jun;ZHANG Guo-wen;XU Ya-nan(College of Life Science,Inner Mongolia University for Nationalities,Tongliao 028000;School of Life Science,Inner MongoliaUniversity,Hohhot 010021)

机构地区：[1]内蒙古民族大学生命科学学院,通辽028000 [2]内蒙古大学生命科学学院,呼和浩特010021

出　　处：《生物技术通报》2018年第12期172-178,共7页Biotechnology Bulletin

基　　金：内蒙古民族大学科学研究基金(NMDYB1747)

摘　　要：探讨核糖体成熟因子dbpA对大肠杆菌DNA复制起始的影响。观察ΔdbpA基因缺失突变体的DNA复制式样、细胞倍增时间、细胞体积等表型变化,并使用温度敏感性试验和蛋白定量实验探究dbpA的作用机理。结果发现与野生型BW25113相比,ΔdbpA突变体出现DNA复制的起始延迟,细胞倍增时间延长,细胞体积减小等表型变化,且在LB培养基比在ABTGcasa培养基中的变化更明显。温度敏感性实验显示DbpA与DnaA、DnaB或DnaC蛋白没有相互作用。蛋白定量实验显示ΔdbpA的细胞内总蛋白和DnaA蛋白含量都减少,且在LB培养基比ABTGcasa培养基中的减少程度更大。因此缺失dbpA导致大肠杆菌DNA复制起始延迟,原因可能是dbpA通过影响细菌内核糖体的组装或翻译过程影响蛋白质的合成,使细胞内总蛋白和DnaA蛋白的含量减少。这为明确dbpA的功能提供参考。This work is to investigate the effect of ribosome maturation factor dbpA on the initiation of DNA replication in Escherichia coli.The phenotype changes such as DNA replication pattern,doubling time and cell size ofΔdbpA deletion mutants were observed,and the temperature sensitivity test and protein quantitative experiment were used to study the action mechanisms of dbpA.The results showed that the mild phenotypic change such as the delayed initiation of DNA replication,prolonged doubling time,declined cell size occurred inΔdbpA cells compared with wild type BW25113.Moreover,the change in LB medium was more obvious than that in ABTGcasa medium.The temperature sensitivity test demonstrated that DbpA did not interact with DnaA,DnaB or DnaC protein.The protein quantitative experiment revealed that the amount of total protein and DnaA protein inΔdbpA cell decreased,and the decrease degree was greater in LB medium than in ABTGcasa medium.Thus,the absence of dbpA leads to the delayed initiation of E.coli DNA replication,the reason of which may be that dbpA affects the protein synthesis through influencing the assembly or translation activity of ribosome,and subsequently reduces the total protein and DnaA protein in cells.This study provides a reference to clarify the function of dbpA.

关 键 词：DBPA 核糖体成熟因子 DNA复制起始 细菌表型 

分 类 号：Q75[生物学—分子生物学]