A Full-Length Group 1 Bacterial Sigma Factor Adopts a Compact Structure Incompatible with DNA Binding
A Full-Length Group 1 Bacterial Sigma Factor Adopts a Compact Structure Incompatible with DNA Binding
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DOI：
10.1016/j.chembiol.2008.09.008
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发表时间：
2008-10-20
影响因子：
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通讯作者：
Muir, Tom W.
中科院分区：
文献类型：
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作者：
Schwartz, Edmund C.;Shekhtman, Alexander;Muir, Tom W.
a因子是细菌转录起始的关键调控因子。通过直接读出启动子DNA序列，它们将核心RNA聚合酶招募到起始位点，从而决定了RNA聚合酶启动子的特异性。第1组sigma因子在对数期生长过程中指导绝大多数转录起始，对生存能力至关重要，由n端序列sigma自动调节（1.1）。我们报道了Thermotoga maritima sigma(A) sigma（1.1）的溶液结构。此外，我们通过使用化学交联策略证明sigma（1.1）与sigma(A)的启动子识别域非常接近。因此，我们提出sigma（1.1）通过稳定无法结合DNA的sigma因子结构域的紧凑组织来抑制游离sigma(A)的启动子DNA结合。
The a factors are the key regulators of bacterial transcription initiation. Through direct read-out of promoter DNA sequence, they recruit the core RNA polymerase to sites of initiation, thereby dictating the RNA polymerase promoter-specificity. The group 1 sigma factors, which direct the vast majority of transcription initiation during log phase growth and are essential for viability, are autoregulated by an N-terminal sequence known as sigma(1.1). We report the solution structure of Thermotoga maritima sigma(A) sigma(1.1). We additionally demonstrate by using chemical crosslinking strategies that sigma(1.1) is in close proximity to the promoter recognition domains of sigma(A). We therefore propose that sigma(1.1) autoinhibits promoter DNA binding of free sigma(A) by stabilizing a compact organization of the sigma factor domains that is unable to bind DNA.