大肠杆菌K-12dnaA突变型的R6K整合抑制菌株的多起点染色体复制  

Multi-origin Usage for Chromosome Replication of Suppressive Integration Strain of dnaA46 Mutant of Escherichia Coli Integrated with R6K

作　　者：卢见微 毛裕民[1] 盛祖嘉[1] 

机构地区：[1]复旦大学遗传学研究所,上海200433

出　　处：《Acta Genetica Sinica》1992年第1期86-92,共7页

基　　金：国家自然科学基金(3870279)~~

摘　　要：大肠杆菌K-12的温度敏感复制发动缺陷突变(dnaA46)菌株LC381不能在42℃中进行染色体复制。在42℃中选取R6K质粒整合抑制菌株,用标记频率测定法测得这一菌株在30℃中染色体复制从正常的复制起点起始,在42℃中则从另外三个起点起始,其中两个曾见报道,把重组突变recA56引入这一菌株,发现由接近正常复制起点起始的染色体复制不受recA突变的影响,由接近正常复制终点起始的染色体复制则受到阻碍,说明由这一位置起始的染色体复制依赖于recA基因。这一实验结果和我们的其他报道相符。The chromosome of temperature sensitive initiation mutant dnaA46 of Escherichia coli K-12 fails to replicate at 42℃. Supprssive integration (Sin) strain integrated with the R6K plasmid was screened at 42℃. Marker frequency determination of the Sin strain reveals that replication was initiated at the normal site of initiation at 30℃, while at three different sites at 42℃. Two of the sites have been reported in the stable DNA replication mutant, one of them is a no-val site. Inhibition of chromosome replication was not observed for the recA derivative of Sin initiated at two of the initiation sites close to the normal initiation site. Inhibition was observed for chromosome replication initiated near the site where chromosome replication normally terminates. It indicates that chromosome replication initiated at sites close to the terminus is recA gene dependent.

关 键 词：整合抑制 复制起点 大肠杆菌 

分 类 号：Q343.24[生物学—遗传学]