The LysR-type regulator QseA regulates both characterized and putative virulence genes in enterohaemorrhagic Escherichia coli O157:H7.
The LysR-type regulator QseA regulates both characterized and putative virulence genes in enterohaemorrhagic Escherichia coli O157:H7.
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DOI：
10.1111/j.1365-2958.2010.07174.x
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发表时间：
2010-06-01
影响因子：
3.6
通讯作者：
Sperandio V
中科院分区：
文献类型：
--
作者：
Kendall MM;Rasko DA;Sperandio V
肠出血性大肠杆菌（EHEC）在大肠中定植，引起附着性和消退性病变（AE）。大多数参与AE病变形成的基因都编码在一个被称为肠细胞湮没位点（LEE）的染色体致病性岛中。lysr型转录因子QseA通过与ler的调控区结合来调控LEE。我们进行了转录组分析，比较了WT EHEC和qseA突变体，以阐明qseA在基因调控中的作用。在两个生长阶段，o岛携带的一些基因被QseA激活，而参与细胞代谢的基因被抑制。在对数生长后期，QseA激活了LEE基因以及非LEE编码的效应蛋白的表达。我们还进行了电泳迁移率转移测定，竞争实验和dna足迹。结果表明，QseA可以直接结合末端近端启动子和远端启动子、其自身启动子以及ehec特异性o岛编码基因的启动子。此外，我们绘制了qseA的转录起始位点，从而鉴定了两个启动子序列。综上所述，这些结果表明QseA在肠出血性大肠杆菌中起着全局调节作用，协调毒力基因的表达。
Enterohemorrhagic E. coli (EHEC) colonizes the large intestine, causing attaching and effacing lesions (AE). Most of the genes involved in AE lesion formation are encoded within a chromosomal pathogenicity island termed the locus of enterocyte effacement (LEE). The LysR-type transcriptional factor QseA regulates the LEE by binding to the regulatory region of ler. We performed transcriptome analyses comparing WT EHEC and the qseA mutant to elucidate QseA’s role in gene regulation. During both growth phases, several genes carried in O-islands were activated by QseA, whereas genes involved in cell metabolism were repressed. During late-logarithmic growth, QseA activated expression of the LEE genes as well as non-LEE encoded effector proteins. We also performed electrophoretic mobility shift assays, competition experiments, and DNAseI footprints. The results demonstrated that QseA directly binds both the ler proximal and distal promoters, its own promoter, as well as promoters of genes encoded in EHEC-specific O-islands. Additionally, we mapped the transcriptional start site of qseA, leading to the identification of two promoter sequences. Taken together, these results indicate that QseA acts as a global regulator in EHEC, coordinating expression of virulence genes.
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影响因子：
15.9
作者：
DONNENBERG, MS;TACKET, CO;LEVINE, MM
通讯作者：
LEVINE, MM
影响因子：
3.6
作者：
Friedberg, D;Umanski, T;Rosenshine, I
通讯作者：
Rosenshine, I
DOI：
10.1073/pnas.89.5.1646
发表时间：
1992-03-01
影响因子：
11.1
作者：
GOETHALS, K;VANMONTAGU, M;HOLSTERS, M
通讯作者：
HOLSTERS, M
影响因子：
2
作者：
COLLIER, PD;CROMIE, DDO;DAVIES, AP
通讯作者：
DAVIES, AP
影响因子：
3.1
作者：
DONNENBERG, MS;KAPER, JB
通讯作者：
KAPER, JB