YjjQ Represses Transcription of flhDC and Additional Loci in Escherichia coli
YjjQ Represses Transcription of flhDC and Additional Loci in Escherichia coli
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DOI：
10.1128/jb.00263-15
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发表时间：
2015-06
影响因子：
3.2
通讯作者：
Helene Wiebe;D. Gürlebeck;Jana Groß;Katrin Dreck;Derk Pannen;C. Ewers;L. Wieler;K. Schnetz
中科院分区：
文献类型：
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作者：
Helene Wiebe;D. Gürlebeck;Jana Groß;Katrin Dreck;Derk Pannen;C. Ewers;L. Wieler;K. Schnetz
摘要转录调控因子YjjQ在禽致病性大肠杆菌（APEC）中具有毒力相关性。在这项工作中，我们的特点YjjQ的flhDC操纵子的转录抑制，编码鞭毛合成的主调节器，和其他位点。后者包括gfc（胶囊4合成）、ompC（外膜孔蛋白C）、yfiRNB（受调节的c-di-GMP合成）和功能不明确的基因座（ybhL和ymiA-yciX）。我们确定了在flhDC和gfc启动子的YjjQ DNA结合位点，并表征了发现被YjjQ抑制的所有启动子中存在的DNA结合序列基序。在flhDC启动子处，YjjQ DNA结合位点与RcsA-RcsB DNA结合位点重叠。RcsA-RcsB同样抑制flhDC启动子，但YjjQ的抑制和RcsA-RcsB的抑制彼此独立。这些数据表明YjjQ是在转录起始水平参与flhDC的复杂控制的另外的调节剂。此外，我们表明YjjQ抑制运动的E。coliK-12实验室菌株和泌尿系致病性E.大肠杆菌（UPEC）菌株CFT 073和536。YjjQ对flhDC、yfiRNB和另外的基因座的调节可能是与致病性相关的特征。重要性大肠杆菌是一种可引起人类和农场动物肠内和肠外感染的致病性细菌。E.大肠杆菌菌株的致病性取决于其特定的基因组含量，其中包括控制宿主环境中细胞生理学的必需和相关毒力因子。然而，大肠杆菌和致病性大肠杆菌的基因库不同。大肠杆菌中没有明确区分，并且需要表征毒力相关位点的功能。在这项研究中，我们描述了yjjQ的功能，它编码一个转录调节因子，被鉴定为与禽致病性大肠杆菌的毒力相关。coli（APEC）。我们的特点YjjQ作为转录抑制鞭毛运动和致病性相关的其他位点。
ABSTRACT The presumptive transcriptional regulator YjjQ has been identified as being virulence associated in avian pathogenic Escherichia coli (APEC). In this work, we characterize YjjQ as transcriptional repressor of the flhDC operon, encoding the master regulator of flagellar synthesis, and of additional loci. The latter include gfc (capsule 4 synthesis), ompC (outer membrane porin C), yfiRNB (regulated c-di-GMP synthesis), and loci of poorly defined function (ybhL and ymiA-yciX). We identify the YjjQ DNA-binding sites at the flhDC and gfc promoters and characterize a DNA-binding sequence motif present at all promoters found to be repressed by YjjQ. At the flhDC promoter, the YjjQ DNA-binding site overlaps the RcsA-RcsB DNA-binding site. RcsA-RcsB likewise represses the flhDC promoter, but the repression by YjjQ and that by RcsA-RcsB are independent of each other. These data suggest that YjjQ is an additional regulator involved in the complex control of flhDC at the level of transcription initiation. Furthermore, we show that YjjQ represses motility of the E. coli K-12 laboratory strain and of uropathogenic E. coli (UPEC) strains CFT073 and 536. Regulation of flhDC, yfiRNB, and additional loci by YjjQ may be features relevant for pathogenicity. IMPORTANCE Escherichia coli is a commensal and pathogenic bacterium causing intra- and extraintestinal infections in humans and farm animals. The pathogenicity of E. coli strains is determined by their particular genome content, which includes essential and associated virulence factors that control the cellular physiology in the host environment. However, the gene pools of commensal and pathogenic E. coli are not clearly differentiated, and the function of virulence-associated loci needs to be characterized. In this study, we characterize the function of yjjQ, encoding a transcription regulator that was identified as being virulence associated in avian pathogenic E. coli (APEC). We characterize YjjQ as transcriptional repressor of flagellar motility and of additional loci related to pathogenicity.