Functional Analysis of theAcinetobacter baumanniiXerC and XerD Site-Specific Recombinases: Potential Role in Dissemination of Resistance Genes
Functional Analysis of theAcinetobacter baumanniiXerC and XerD Site-Specific Recombinases: Potential Role in Dissemination of Resistance Genes
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DOI：
10.3390/antibiotics9070405
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发表时间：
2020-07-01
影响因子：
4.8
通讯作者：
Tolmasky, Marcelo E.
中科院分区：
文献类型：
--
作者：
Lin, David L.;Traglia, German M.;Tolmasky, Marcelo E.
由抗性基因组成的模块两侧是Xer位点特异性重组位点，其中绝大多数是在鲍曼不动杆菌中发现的，被认为是促进水平传播的元件。西娅。克隆了鲍曼杆菌和大肠杆菌基因，并将重组克隆用于补充同源大肠杆菌共变物。补充菌株支持质粒二聚体的分辨率，并且与情况一样。大肠杆菌和肺炎克雷伯菌质粒，当细胞在低渗透压培养基中生长时，活性增强。结合实验表明，部分纯化的eda。baumanniiXerC和XerD蛋白（XerC（Ab）和XerD(Ab)）结合合成的Xer位点特异性重组位点，其中一些核苷酸序列是从存在的a中推断出来的。baumanniiplasmids。与自杀底物孵育导致DNA与重组酶（可能是XerC(Ab)）的共价附着，表明重组反应的第一步发生了。结果表明，XerC（Ab）和XerD（Ab）是功能性蛋白，支持了它们参与耐药基因在细菌间水平传播的假设。
Modules composed of a resistance gene flanked by Xer site-specific recombination sites, the vast majority of which were found inAcinetobacter baumannii, are thought to behave as elements that facilitate horizontal dissemination. TheA. baumanniixerCandxerDgenes were cloned, and the recombinant clones used to complement the cognateEscherichia colimutants. The complemented strains supported the resolution of plasmid dimers, and, as is the case withE. coliandKlebsiella pneumoniaeplasmids, the activity was enhanced when the cells were grown in a low osmolarity growth medium. Binding experiments showed that the partially purifiedA. baumanniiXerC and XerD proteins (XerC(Ab)and XerD(Ab)) bound synthetic Xer site-specific recombination sites, some of them with a nucleotide sequence deduced from existingA. baumanniiplasmids. Incubation with suicide substrates resulted in the covalent attachment of DNA to a recombinase, probably XerC(Ab), indicating that the first step in the recombination reaction took place. The results described show that XerC(Ab)and XerD(Ab)are functional proteins and support the hypothesis that they participate in horizontal dissemination of resistant genes among bacteria.