Two DNA sites for MelR in the same orientation are sufficient for optimal MelR-dependent repression at the Escherichia coli melR promoter
Two DNA sites for MelR in the same orientation are sufficient for optimal MelR-dependent repression at the Escherichia coli melR promoter
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DOI：
10.1111/1574-6968.12027
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发表时间：
2013-01-01
影响因子：
2.1
通讯作者：
Busby, Stephen J. W.
中科院分区：
文献类型：
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作者：
Elrobh, Mohamed S.;Webster, Christine L.;Busby, Stephen J. W.
大肠杆菌melR基因编码控制蜜二糖利用的MelR转录因子。melR的表达由MelR自动调节，MelR通过结合与转录起始重叠的靶标来抑制melR启动子。在这里，我们表明，MelR依赖的抑制的MelR启动子可以增强由MelR位于上游250个碱基对的第二个单一的DNA位点的存在。平行于AraC依赖的镇压在araCaraBAD调节区和MelR依赖的镇压环形成的可能性进行了讨论。结果表明，MelR结合在两个远端位点可以协同转录抑制。
The Escherichia coli melR gene encodes the MelR transcription factor that controls melibiose utilization. Expression of melR is autoregulated by MelR, which represses the melR promoter by binding to a target that overlaps the transcript start. Here, we show that MelR-dependent repression of the melR promoter can be enhanced by the presence of a second single DNA site for MelR located up to 250 base pairs upstream. Parallels with AraC-dependent repression at the araCaraBAD regulatory region and the possibility of the MelR-dependent repression loop formation are discussed. The results show that MelR bound at two distal loci can cooperate together in transcriptional repression.