Interaction of the antiactivator FleN with the transcriptional activator FleQ regulates flagellar number in Pseudomonas aeruginosa
Interaction of the antiactivator FleN with the transcriptional activator FleQ regulates flagellar number in Pseudomonas aeruginosa
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DOI：
10.1128/jb.183.22.6636-6644.2001
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发表时间：
2001-11-01
影响因子：
3.2
通讯作者：
Ramphal, R
中科院分区：
文献类型：
--
作者：
Dasgupta, N;Ramphal, R
铜绿假单胞菌鞭毛数量受FleN控制，FleN是一种假定的ATP/GTP结合蛋白。len1的破坏导致单鞭毛菌株PAK和PAO1的多鞭毛，并与趋化缺陷有关。我们认为鞭毛数量是由抗激活因子FleN维持的，它通过与鞭毛基因的转录激活因子FleQ结合而下调鞭毛基因，FleQ是一种属于NifA亚家族的增强子结合蛋白。在本报告中，我们证明了FleN和FleQ在酵母双杂交系统中的直接相互作用。FleN24K中假定的ATP/GTP结合基序→Qand在N或C端截断FleN的突变消除了这种相互作用。FleN在体外不抑制FleQ的DNA结合能力，这表明它可能利用另一种机制作为FleQ的抗激活剂。
Flagellar number inPseudomonas aeruginosais controlled by FleN, a putative ATP/GTP binding protein. Disruption offleNresults in multiflagellation of the otherwise monoflagellate strains PAK and PAO1 and is associated with a chemotactic defect. We propose that flagellar number is maintained by the antiactivator FleN, which downregulates flagellar genes by binding to their transcriptional activator, FleQ, an enhancer binding protein belonging to the NifA subfamily. In this report we demonstrate direct interaction of FleN and FleQ in the yeast two-hybrid system. Mutagenesis of the putative ATP/GTP binding motif in FleN24K→Qand truncation of FleN at either the N or C terminus abrogates this interaction. FleN does not inhibit the DNA binding ability of FleQ in vitro, thus indicating that it probably utilizes another mechanism(s) to serve as a FleQ antiactivator.