Identification of the activating region of catabolite gene activator protein (CAP): isolation and characterization of mutants of CAP specifically defective in transcription activation.
Identification of the activating region of catabolite gene activator protein (CAP): isolation and characterization of mutants of CAP specifically defective in transcription activation.
复制标题
分解代谢物基因激活蛋白 (CAP) 激活区域的鉴定：转录激活特异性缺陷的 CAP 突变体的分离和表征。
DOI：
10.1073/pnas.90.13.6081
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发表时间：
1993
影响因子：
11.1
通讯作者：
Ebright,RH
中科院分区：
文献类型：
--
作者：
Zhou,Y;Zhang,X;Ebright,RH
我们已经分离出21个突变体的分解代谢物基因激活蛋白（CAP）在乳糖启动子的转录激活缺陷，但没有缺陷的DNA结合。突变体中的氨基酸取代映射到CAP的单个区域：氨基酸156-162。如体外评估的，取代的CAP变体几乎完全不能激活lac启动子处的转录，但以与野生型CAP相同的亲和力结合DNA并使DNA弯曲至与野生型CAP相同的程度。我们的研究结果表明，氨基酸156-162是关键的转录激活在乳糖启动子，但不是DNA结合和DNA弯曲。在CAP的结构中，氨基酸156-162是表面环的一部分。我们建议，这个表面环使直接的蛋白质-蛋白质接触RNA聚合酶在乳糖启动子。
We have isolated 21 mutants of catabolite gene activator protein (CAP) defective in transcription activation at the lac promoter but not defective in DNA binding. The amino acid substitutions in the mutants map to a single region of CAP: amino acids 156-162. As assessed in vitro, the substituted CAP variants are nearly completely unable to activate transcription at the lac promoter but bind to DNA with the same affinity and bend DNA to the same extent as wild-type CAP. Our results establish that amino acids 156-162 are critical for transcription activation at the lac promoter but not for DNA binding and DNA bending. In the structure of CAP, amino acids 156-162 are part of a surface loop. We propose that this surface loop makes a direct protein-protein contact with RNA polymerase at the lac promoter.