...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of bacteriology >Two Roles for the DNA Recognition Site of theKlebsiella aerogenes Nitrogen Assimilation Control Protein
【24h】

Two Roles for the DNA Recognition Site of theKlebsiella aerogenes Nitrogen Assimilation Control Protein

机译：产气克雷伯菌氮同化控制蛋白的DNA识别位点的两个作用。

获取原文
   

获取外文期刊封面封底 >>

       
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The nitrogen assimilation control protein (NAC) binds to a site within the promoter region of the histidine utilization operon (hutUH) of Klebsiella aerogenes, and NAC bound at this site activates transcription of hutUH. This NAC-binding site was characterized by a combination of random and directed DNA mutagenesis. Mutations that abolished or diminished in vivo transcriptional activation by NAC were found to lie within a 15-bp region contained within the 26-bp region protected by NAC from DNase I digestion. This 15-bp core has the palindromic ends ATA and TAT, and it matches the consensus for LysR family transcriptional regulators. Protein-binding experiments showed that transcriptional activation in vivo decreased with decreasing binding in vitro. In contrast to the NAC-binding site from hutUH, the NAC-binding site from thegdhA promoter failed to activate transcription from a semisynthetic promoter, and this failure was not due to weak binding or greatly distorted protein-DNA structure. Mutations in the promoter-proximal half-site of the NAC-binding site fromgdhA allowed this site to activate transcription. Similar studies using the NAC-binding site from hut showed that two mutations in the promoter proximal half-site increased binding but abolished transcriptional activation. Interestingly, for symmetric mutations in the promoter-distal half-site, loss of transcriptional activation was always correlated with a decrease in binding. We conclude from these observations that if the binding in vitro reflects the binding in vivo, then binding of NAC to DNA is not sufficient for transcriptional activation and that the NAC-binding site can be functionally divided in two half-sites, with related but different functions.
机译：氮同化控制蛋白（NAC）结合至产气单胞菌（Kembsiella aerogenes）的组氨酸利用操纵子（ hutUH ）的启动子区域内的一个位点，结合在该位点的NAC激活转录 hutUH 。该NAC结合位点的特征在于随机和定向DNA诱变的组合。发现通过NAC消除或减弱了体内转录激活的突变位于NAC保护免于DNase I消化的26 bp区域内的15 bp区域内。这个15 bp的核心具有回文末端ATA和TAT，并且与LysR家族的转录调节子一致。蛋白质结合实验表明，体内转录激活随体外结合减少而降低。与 hutUH 的NAC结合位点相反， gdhA 启动子的NAC结合位点不能激活半合成启动子的转录，并且这种失败不是由于弱结合或蛋白质-DNA结构严重扭曲。来自 gdhA 的NAC结合位点的启动子近端半位点发生突变，使该位点可以激活转录。使用 hut 的NAC结合位点进行的类似研究表明，启动子近端半位点中的两个突变增加了结合，但消除了转录激活。有趣的是，对于启动子远端半位点的对称突变，转录激活的丧失总是与结合的减少相关。我们从这些观察结果得出结论，如果体外结合反映了体内结合，则NAC与DNA的结合不足以实现转录激活，并且NAC结合位点可以在功能上分为两个半位，相关但不同职能。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号