Escherichia coli topoisomerase I is an iron and zinc binding protein.
Escherichia coli topoisomerase I is an iron and zinc binding protein.
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大肠杆菌拓扑异构酶 I 是一种铁和锌结合蛋白
DOI：
10.1007/s10534-011-9425-6
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发表时间：
2011-08
期刊：
影响因子：
3.5
通讯作者：
Ding, Huangen
中科院分区：
文献类型：
--
作者：
Lu, Jianxin;Wang, Wu;Tan, Guoqiang;Landry, Aaron P.;Yi, Peng;Si, Fan;Ren, Yaguang;Ding, Huangen
大肠杆菌拓扑异构酶I（TopA）切割并重新连接双链DNA的一条链以松弛负超螺旋DNA。在结构上，TopA含有一个N-末端催化片段和一个C-末端锌结合区，这是负超螺旋DNA松弛所必需的。在这里，我们报告，E。coli TopA是一种铁和锌结合蛋白。紫外-可见吸收光谱和金属含量分析表明，从E.在富含铁和锌的LB培养基中生长的大肠杆菌细胞。而从E.在M9基本培养基中生长的大肠杆菌细胞具有可忽略的量的锌或铁，并且没有拓扑异构酶活性。但补充外源锌或铁对大肠杆菌的生长发育有一定的影响。在M9基本培养基中生长的大肠杆菌细胞分别产生锌或铁结合的TopA。而锌结合的TopA是完全活性的负超螺旋DNA的放松，铁结合的TopA有很少或没有酶活性。此外，M9基本培养基中过量的铁能够与E. coli细胞中的拓扑异构酶活性，表明E.在体内铁和锌的结合可以调节大肠杆菌TopA的表达。
Escherichia coli topoisomerase I (TopA) cleaves and rejoins one strand of double-stranded DNA to relax the negatively supercoiled DNA. Structurally, TopA contains an N-terminal catalytic fragment and a C-terminal zinc-binding region that is required for relaxation of the negatively supercoiled DNA. Here we report that E. coli TopA is an iron and zinc binding protein. The UV-Vis absorption measurements and metal content analyses reveal that TopA purified from E. coli cells grown in the rich LB medium contains both iron and zinc. However, TopA purified from E. coli cells grown in the M9 minimal medium has negligible amounts of zinc or iron and no topoisomerase activity. Nevertheless, supplement of exogenous zinc or iron in E. coli cells grown in the M9 minimal medium produces the zinc- or iron-bound TopA, respectively. Whereas the zinc-bound TopA is fully active to relax the negatively supercoiled DNA, the iron-bound TopA has little or no enzyme activity. Furthermore, excess iron in the M9 minimal medium is able to compete with the zinc binding in TopA in E. coli cells and attenuate the topoisomerase activity, suggesting that E. coli TopA may be modulated by iron and zinc binding in vivo.
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影响因子：
5.6
作者：
Bae, JB;Park, JH;Roe, JH
通讯作者：
Roe, JH
影响因子：
3
作者：
Besold, Angelique N.;Lee, Seung Jae;Cymet, Holly J.
通讯作者：
Cymet, Holly J.
DOI：
10.1073/pnas.93.17.8836
发表时间：
1996-08-20
影响因子：
11.1
作者：
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通讯作者：
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影响因子：
14.9
作者：
Tse-Dinh YC
通讯作者：
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影响因子：
14.9
作者：
Forterre P;Gadelle D
通讯作者：
Gadelle D