首页> 外文OA文献 >Bacillus cereus DNA topoisomerase I and IIIα: purification, characterization and complementation of Escherichia coli TopoIII activity
【2h】

Bacillus cereus DNA topoisomerase I and IIIα: purification, characterization and complementation of Escherichia coli TopoIII activity

机译:蜡状芽孢杆菌DNA拓扑异构酶I和IIIα:大肠杆菌TopoIII活性的纯化,表征和互补

代理获取
本网站仅为用户提供外文OA文献查询和代理获取服务,本网站没有原文。下单后我们将采用程序或人工为您竭诚获取高质量的原文,但由于OA文献来源多样且变更频繁,仍可能出现获取不到、文献不完整或与标题不符等情况,如果获取不到我们将提供退款服务。请知悉。

摘要

The Bacillus cereus genome possesses three type IA topoisomerase genes. These genes, encoding DNA topoisomerase I and IIIα (bcTopo I, bcTopo IIIα), have been cloned into T7 RNA polymerase-regulated plasmid expression vectors and the enzymes have been overexpressed, purified and characterized. The proteins exhibit similar biochemical activity to their Escherichia coli counterparts, DNA topoisomerase I and III (ecTopo I, ecTopo III). bcTopo I is capable of efficiently relaxing negatively supercoiled DNA in the presence of Mg2+ but does not possess an efficient DNA decatenation activity. bcTopo IIIα is an active topoisomerase that is capable of relaxing supercoiled DNA at a broad range of Mg2+ concentrations; however, its DNA relaxation activity is not as efficient as that of bcTopo I. In addition, bcTopo III is a potent DNA decatenase that resolves oriC-based plasmid replication intermediates in vitro. Interestingly, bcTopo I and bcTopo IIIα are both able to compensate for the loss of ecTopo III in E.coli cells that lack ecTopo I. In contrast, ecTopo I cannot substitute for ecTopo III under these conditions.
机译:蜡状芽孢杆菌基因组具有三个IA型拓扑异构酶基因。这些编码DNA拓扑异构酶I和IIIα(bcTopo I,bcTopoIIIα)的基因已被克隆到T7 RNA聚合酶调控的质粒表达载体中,并且这些酶已经过表达,纯化和鉴定。这些蛋白质与其大肠杆菌对应的DNA拓扑异构酶I和III(ecTopo I,ecTopo III)具有相似的生化活性。在Mg2 +存在下,bcTopo I能够有效地使负超螺旋DNA松弛,但不具有有效的DNA脱界活性。 bcTopoIIIα是一种活性拓扑异构酶,能够在很宽的Mg2 +浓度范围内使超螺旋DNA松弛;但是,其DNA松弛活性不如bcTopo I高效。此外,bcTopo III是有效的DNA脱氢酶,可在体外解析基于oriC的质粒复制中间体。有趣的是,bcTopo I和bcTopoIIIα都能够补偿缺少ecTopo I的大肠杆菌细胞中ecTopo III的损失。相反,在这些条件下ecTopo I不能替代ecTopo III。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
代理获取

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号