caa a22 4500 445321717 CHVBK 20180317142706.0 cr unu---uuuuu 170323e20110801xx s 000 0 eng 10.1007/s10534-011-9425-6 doi (NATIONALLICENCE)springer-10.1007/s10534-011-9425-6 Escherichia coli topoisomerase I is an iron and zinc binding protein [Elektronische Daten] [Jianxin Lu, Wu Wang, Guoqiang Tan, Aaron Landry, Peng Yi, Fan Si, Yaguang Ren, Huangen Ding] 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. Springer Science+Business Media, LLC., 2011 Topoisomerase I nationallicence Zinc nationallicence Iron nationallicence Metalloprotein nationallicence TopA : E. coli topoisomerase I nationallicence EPR : Electron paramagnetic resonance nationallicence Lu Jianxin Laboratory of Molecular Medicine, Wenzhou Medical College, 325035, Wenzhou, Zhejiang, People's Republic of China aut Wang Wu Laboratory of Molecular Medicine, Wenzhou Medical College, 325035, Wenzhou, Zhejiang, People's Republic of China aut Tan Guoqiang Laboratory of Molecular Medicine, Wenzhou Medical College, 325035, Wenzhou, Zhejiang, People's Republic of China aut Landry Aaron Department of Biological Sciences, Louisiana State University, 202 Life Sciences Building, 70803, Baton Rouge, LA, USA aut Yi Peng Laboratory of Molecular Medicine, Wenzhou Medical College, 325035, Wenzhou, Zhejiang, People's Republic of China aut Si Fan Laboratory of Molecular Medicine, Wenzhou Medical College, 325035, Wenzhou, Zhejiang, People's Republic of China aut Ren Yaguang Laboratory of Molecular Medicine, Wenzhou Medical College, 325035, Wenzhou, Zhejiang, People's Republic of China aut Ding Huangen Laboratory of Molecular Medicine, Wenzhou Medical College, 325035, Wenzhou, Zhejiang, People's Republic of China aut BioMetals Springer Netherlands 24/4(2011-08-01), 729-736 0966-0844 24:4<729 2011 24 10534 https://doi.org/10.1007/s10534-011-9425-6 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10534-011-9425-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Lu Jianxin Laboratory of Molecular Medicine, Wenzhou Medical College, 325035, Wenzhou, Zhejiang, People's Republic of China aut NATIONALLICENCE 700 1- Wang Wu Laboratory of Molecular Medicine, Wenzhou Medical College, 325035, Wenzhou, Zhejiang, People's Republic of China aut NATIONALLICENCE 700 1- Tan Guoqiang Laboratory of Molecular Medicine, Wenzhou Medical College, 325035, Wenzhou, Zhejiang, People's Republic of China aut NATIONALLICENCE 700 1- Landry Aaron Department of Biological Sciences, Louisiana State University, 202 Life Sciences Building, 70803, Baton Rouge, LA, USA aut NATIONALLICENCE 700 1- Yi Peng Laboratory of Molecular Medicine, Wenzhou Medical College, 325035, Wenzhou, Zhejiang, People's Republic of China aut NATIONALLICENCE 700 1- Si Fan Laboratory of Molecular Medicine, Wenzhou Medical College, 325035, Wenzhou, Zhejiang, People's Republic of China aut NATIONALLICENCE 700 1- Ren Yaguang Laboratory of Molecular Medicine, Wenzhou Medical College, 325035, Wenzhou, Zhejiang, People's Republic of China aut NATIONALLICENCE 700 1- Ding Huangen Laboratory of Molecular Medicine, Wenzhou Medical College, 325035, Wenzhou, Zhejiang, People's Republic of China aut NATIONALLICENCE 773 0- BioMetals Springer Netherlands 24/4(2011-08-01), 729-736 0966-0844 24:4<729 2011 24 10534 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer