In vivo studies on the positive control function of NifA:: a conserved hydrophobic amino acid patch at the central domain involved in transcriptional activation
In vivo studies on the positive control function of NifA:: a conserved hydrophobic amino acid patch at the central domain involved in transcriptional activation
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DOI：
10.1046/j.1365-2958.1998.00772.x
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发表时间：
1998-04-01
影响因子：
3.6
通讯作者：
Morett, E
中科院分区：
文献类型：
--
作者：
González, V;Olvera, L;Morett, E
真细菌增强子结合蛋白通过与远端位点结合并同时接触RNA聚合酶sigma（54）启动子复合物（E sigma（54））来激活转录。正调控功能位于这些蛋白质的中心结构域，但不知道哪个特定区域具有与E σ相互作用的决定因素（54）。在这里，我们提出的遗传证据表明，一个小区域的疏水性氨基酸，以前命名为C3，在中央域的慢生型大豆根瘤菌NifA参与阳性对照。我们沿着这个保守区域获得了26个错义突变体沿着。在这些菌株中，只有表达NifA（F307-->Y）和NifA（310-->S）突变蛋白的菌株保留了一些转录活性（D），而NifA（T308-->S）具有非常低但可检测的活性（
The eubacterial enhancer-binding proteins activate transcription by binding to distant sites and, simultaneously, contacting the RNA polymerase sigma(54) promoter complex (E sigma(54)). Th, positive control function is located at the central domain of these proteins, but it is not know which specific region has the determinants for the interaction with E sigma(54). Here, we present genetic evidence that a small region of hydrophobic amino acids, previously denominated C3, at the central domain of Bradyrhizobium japonicum NifA is involved in positive control. We obtained 26 missense mutants along this conserved region. Among these, only strains expressing the NifA(F307-->Y) and NifA(310-->S) mutant proteins retained some of the transcriptional activity (D) and NifA(T308-->S) had very low but detectable activity (