Bacillus cereus DNA topoisomerase I and IIIalpha: purification, characterization and complementation of Escherichia coli TopoIII activity.
Bacillus cereus DNA topoisomerase I and IIIalpha: purification, characterization and complementation of Escherichia coli TopoIII activity.
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蜡状芽孢杆菌DNA拓扑异构酶I和iiialpha：大肠杆菌拓扑tpoIII活性的纯化，表征和互补。
DOI：
10.1093/nar/gki846
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发表时间：
2005
影响因子：
14.9
通讯作者：
DiGate, R
中科院分区：
文献类型：
--
作者：
Li, ZY;Hiasa, H;DiGate, R
蜡状芽孢杆菌基因组具有三个IA型拓扑异构酶基因。这些基因编码DNA拓扑异构酶I和IIIα（bcTopo I，bcTopo IIIα），已被克隆到T7 RNA聚合酶调控的质粒表达载体中，并已过表达，纯化和表征的酶。这些蛋白质表现出与它们的大肠杆菌对应物DNA拓扑异构酶I和III（ecTopo I、ecTopo III）相似的生物化学活性。bcTopo I能够在Mg 2+存在下有效地松弛负超螺旋DNA，但不具有有效的DNA脱链活性。bcTopo IIIα是一种活性拓扑异构酶，能够在广泛的Mg 2+浓度范围内松弛超螺旋DNA;然而，其DNA松弛活性不如bcTopo I有效。此外，bcTopo III是一种有效的DNA decatenase，可在体外分解基于oriC的质粒复制中间体。有趣的是，bcTopo I和bcTopo IIIα都能够补偿缺乏ecTopo I的大肠杆菌细胞中ecTopo III的损失。相比之下，在这些条件下，ecTopo I无法替代ecTopo III。
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.
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DOI：
10.1073/pnas.0335853100
发表时间：
2003-02-04
影响因子：
11.1
作者：
Brüggemann, H;Bäumer, S;Gottschalk, G
通讯作者：
Gottschalk, G
影响因子：
3.5
作者：
CEGLOWSKI, P;BOITSOV, A;ALONSO, JC
通讯作者：
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DOI：
10.1073/pnas.0402414101
发表时间：
2004-06-01
影响因子：
11.1
作者：
Hoffmaster, AR;Ravel, J;Fraser, CM
通讯作者：
Fraser, CM
影响因子：
3.6
作者：
Li, ZY;Mondragón, A;DiGate, RJ
通讯作者：
DiGate, RJ
影响因子：
5.7
作者：
Mondragón, A;DiGate, R
通讯作者：
DiGate, R