MECHANISM OF ARAC AUTO-REGULATION AND THE DOMAINS OF 2 OVERLAPPING PROMOTERS, PC AND PBAD, IN THE L-ARABINOSE REGULATORY REGION OF ESCHERICHIA-COLI
MECHANISM OF ARAC AUTO-REGULATION AND THE DOMAINS OF 2 OVERLAPPING PROMOTERS, PC AND PBAD, IN THE L-ARABINOSE REGULATORY REGION OF ESCHERICHIA-COLI
复制标题
DOI：
10.1073/pnas.78.2.752
复制
发表时间：
1981-01-01
期刊：
影响因子：
--
通讯作者：
WALLACE, RG
中科院分区：
文献类型：
--
作者：
LEE, NL;GIELOW, WO;WALLACE, RG
通过使用甲基化保护和 DNase I 保护方法，确定了 ara 调节区（包含 araBAD 和 araC 启动子）中 araC 蛋白、cAMP 结合蛋白和 RNA 聚合酶的 DNA-蛋白接触位点。通过将这些位点的占据状态与转录起始中的启动子活性相关联来评估结合的功能意义。结果表明，araC 自动调节的基础是 araC 蛋白，无论是激活子 (P2) 还是阻遏子 (P1) 形式，通过与 araC 启动子上的 RNA 聚合酶附着位点结合，充当 araC 的阻遏子。 araC 和 araBAD 启动子共享一个受 cAMP 结合蛋白正控制的共同位点，该位点距 araBAD 90 个碱基，距 araC 转录起始点 60 个碱基。提出了分解代谢基因激活蛋白 P1 和 P2 调节 araBAD 和 araC 表达的机制模型。 Ogden 等人提出的早期模型。 （1980）进行了讨论。
The DNA-protein contact sites in the ara regulatory region, which contains the promoters for araBAD and araC, were determined for araC protein, the cAMP-binding protein and RNA polymerase by using the methylation protection and DNase I protection methods. The functional significance of binding was assessed by correlating the state of occupancy of these sites with promoter activity in transcription initiation. Results suggest that the basis for araC autoregulation is that araC protein, in either its activator (P2) or repressor (P1) form, acts as a repressor for araC, by binding to the RNA polymerase attachment site at the araC promoter. The araC and araBAD promoters share a common site of positive control by the cAMP-binding protein, located 90 bases from the araBAD and 60 bases from the araC transcriptional start points. A model for the mechanism of regulation of araBAD and araC expression by the catabolite gene-activator protein, P1, and P2 is proposed. An earlier model proposed by Ogden et al. (1980) is discussed.