The transcriptional regulator RfaH stimulates RNA chain synthesis after recruitment to elongation complexes by the exposed nontemplate DNA strand
The transcriptional regulator RfaH stimulates RNA chain synthesis after recruitment to elongation complexes by the exposed nontemplate DNA strand
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DOI：
10.1016/s0092-8674(02)00724-9
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发表时间：
2002-04-19
期刊：
影响因子：
64.5
通讯作者：
Landick, R
中科院分区：
文献类型：
--
作者：
Artsimovitch, I;Landick, R
转录调控蛋白RfaH控制细菌中编码胞外成分的几个操纵子的表达。RfaH的调节发生在转录延伸过程中，依赖于一个名为OPs的5‘端转录核酸序列，它在体外和体内诱导转录暂停。我们报道，RfaH通过与Ops暂停转录复合体暴露的非模板DNA链中的Ops序列相互作用，识别转录RfaH调节的操纵子的RNA聚合酶。虽然RfaH延迟逃逸OPS暂停，但一旦发生逃逸，RfaH通过抑制暂停和p依赖的终止而增强伸长，而不明显涉及其他辅助蛋白。这一活性预测了RfaH在体内对含有OPs操纵子的调控的累积抗终止模型。
The transcriptional regulatory protein RfaH controls expression of several operons that encode extracytoplasmic components in bacteria. Regulation by RfaH occurs during transcript elongation and depends on a 5'-proximal, transcribed nucleic acid sequence called ops that induces transcriptional pausing in vitro and in vivo. We report that RfaH recognizes RNA polymerase transcribing RfaH-regulated operons by interacting with the ops sequence in the exposed nontemplate DNA strand of ops-paused transcription complexes. Although RfaH delays escape from the ops pause, once escape occurs, RfaH enhances elongation by suppressing pausing and p-dependent termination without apparent involvement of other accessory proteins. This activity predicts a cumulative antitermination model for RfaH's regulation of ops-containing operons in vivo.