Characterization of DNA topoisomerase I from Mycobacterium tuberculosis: DNA cleavage and religation properties and inhibition of its activity
Characterization of DNA topoisomerase I from Mycobacterium tuberculosis: DNA cleavage and religation properties and inhibition of its activity
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DOI：
10.1016/j.abb.2012.10.004
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发表时间：
2012-12-15
影响因子：
3.9
通讯作者：
Nagaraja, Valakunja
中科院分区：
文献类型：
--
作者：
Godbole, Adwait Anand;Leelaram, Majety Naga;Nagaraja, Valakunja
来自细菌的I型DNA拓扑异构酶以Mg 2+依赖的方式催化负超螺旋DNA的松弛。虽然不同类别的拓扑异构酶已经用于抗癌和抗感染药物的开发，但细菌I型酶在这方面远远落后。我们的研究与耻垢分枝杆菌拓扑异构酶I（MstopoI）揭示了它的几个不同的性能相比，充分研究大肠杆菌拓扑异构酶I（EctopoI），这表明针对抑制剂开发的分枝杆菌酶的可能性。在这里，我们描述结核分枝杆菌拓扑异构酶I（MttopoI），并比较其性质与MstopoI和EctopoI。该酶在优选位点切割DNA，其模式与其来自M的直系同源物相似。恶臭含有特异性识别序列的寡核苷酸以类似于MstopoI的方式抑制酶的活性。取代的酸性残基，D111和E115，这是参与镁配位，丙氨酸影响DNA松弛活性。与野生型酶不同，D111A依赖于Mg 2+进行DNA切割，并且两种突变体在再连接中受到损害。针对MstopoI开发的单克隆抗体（mAb）2F3G4抑制MttopoI的舒张活性。这些研究证实了MttopoI的特征与MstopoI相似，并为开发特异性小分子抑制剂奠定了基础。(C)2012 Elsevier Inc. All rights reserved.
Type I DNA topoisomerases from bacteria catalyse relaxation of negatively supercoiled DNA in a Mg2+ dependent manner. Although topoisomerases of distinct classes have been subjected for anti-cancer and anti-infective drug development, bacterial type I enzymes are way behind in this regard. Our studies with Mycobacterium smegmatis topoisomerase I (MstopoI) revealed several of its distinct properties compared to the well studied Escherichia coli topoisomerase I (EctopoI) suggesting the possibility of targeting the mycobacterial enzyme for inhibitor development. Here, we describe Mycobacterium tuberculosis topoisomerase I (MttopoI) and compare its properties with MstopoI and EctopoI. The enzyme cleaves DNA at preferred sites in a pattern similar to its ortholog from M. smegmatis. Oligonucleotides containing the specific recognition sequence inhibited the activity of the enzyme in a manner similar to that of MstopoI. Substitution of the acidic residues, D111 and E115 which are involved in Mg2+ co-ordination, to alanines affected the DNA relaxation activity. Unlike the wild type enzyme, D111A was dependent on Mg2+ for DNA cleavage and both the mutants were compromised in religation. The monoclonal antibody (mAb), 2F3G4, developed against MstopoI inhibited the relaxation activity of MttopoI. These studies affirm the characteristics of MttopoI to be similar to MstopoI and set a stage to target it for the development of specific small molecule inhibitors. (C) 2012 Elsevier Inc. All rights reserved.