Prevalence of SOS-mediated control of integron integrase expression as an adaptive trait of chromosomal and mobile integrons.
Prevalence of SOS-mediated control of integron integrase expression as an adaptive trait of chromosomal and mobile integrons.
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DOI：
10.1186/1759-8753-2-6
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发表时间：
2011-04-30
期刊：
影响因子：
4.9
通讯作者：
Erill I
中科院分区：
文献类型：
--
作者：
Cambray G;Sanchez-Alberola N;Campoy S;Guerin É;Da Re S;González-Zorn B;Ploy MC;Barbé J;Mazel D;Erill I
整合子存在于数百种环境细菌物种中，但主要被认为是负责革兰氏阴性病原体之间的耐药性决定簇的捕获和传播的因子。SOS反应是在阻遏蛋白莱克萨控制下的调节网络，其靶向解决DNA损伤，从而在应激时促进遗传变异。我们最近报道了SOS反应和霍乱弧菌整合子整合酶表达之间的直接联系，以及质粒携带的1类移动的整合子。SOS调节增强了压力条件下的盒交换和捕获，同时在稳定的环境中冻结整合子。我们对整合子整合酶启动子序列进行了系统研究，以分析细菌结构域中这种关系的程度。我们的研究结果表明，莱克萨控制的大部分整合子整合酶的表达，结合大肠杆菌样莱克萨结合位点。此外，结果提供了实验验证的整合酶基因的莱克萨控制的另一个弧菌染色体整合子和一个多抗性质粒窝藏两个整合子。缺乏莱克萨控制和预测的整合酶基因失活之间存在显著相关性，即使实验证据也表明莱克萨调节可能会丢失以增强整合子盒的表达。对整合子整合酶基因的稳态重建使我们得出结论，祖先整合子已经被莱克萨调节。这些数据还表明SOS调节在移动的整合子和大的染色体整合子中被积极地保留，表明未调节的整合酶活性被选择性地抑制。尽管如此，额外的适应可能已经出现，以应付不受管制的整合酶活性。鉴定它们可能是解释细菌结构域中整合子不均匀分布的基础。
Integrons are found in hundreds of environmental bacterial species, but are mainly known as the agents responsible for the capture and spread of antibiotic-resistance determinants between Gram-negative pathogens. The SOS response is a regulatory network under control of the repressor protein LexA targeted at addressing DNA damage, thus promoting genetic variation in times of stress. We recently reported a direct link between the SOS response and the expression of integron integrases in Vibrio cholerae and a plasmid-borne class 1 mobile integron. SOS regulation enhances cassette swapping and capture in stressful conditions, while freezing the integron in steady environments. We conducted a systematic study of available integron integrase promoter sequences to analyze the extent of this relationship across the Bacteria domain. Our results showed that LexA controls the expression of a large fraction of integron integrases by binding to Escherichia coli-like LexA binding sites. In addition, the results provide experimental validation of LexA control of the integrase gene for another Vibrio chromosomal integron and for a multiresistance plasmid harboring two integrons. There was a significant correlation between lack of LexA control and predicted inactivation of integrase genes, even though experimental evidence also indicates that LexA regulation may be lost to enhance expression of integron cassettes. Ancestral-state reconstruction on an integron integrase phylogeny led us to conclude that the ancestral integron was already regulated by LexA. The data also indicated that SOS regulation has been actively preserved in mobile integrons and large chromosomal integrons, suggesting that unregulated integrase activity is selected against. Nonetheless, additional adaptations have probably arisen to cope with unregulated integrase activity. Identifying them may be fundamental in deciphering the uneven distribution of integrons in the Bacteria domain.
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影响因子：
10.7
作者：
Castresana, J
通讯作者：
Castresana, J
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