Regulatory regions of two transport operons under nitrogen control: nucleotide sequences.
Regulatory regions of two transport operons under nitrogen control: nucleotide sequences.
复制标题
氮控制下两个转运操纵子的调节区：核苷酸序列。
DOI：
10.1073/pnas.79.4.1083
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发表时间：
1982
影响因子：
11.1
通讯作者：
Ames,GF
中科院分区：
文献类型：
--
作者：
Higgins,CF;Ames,GF
我们已经确定了从两个氨基酸转运操纵子从鼠伤寒沙门氏菌的调控区的核苷酸序列：dhuA，它调节组氨酸转运操纵子，和argTr，它调节argT，编码赖氨酸-精氨酸-鸟氨酸结合蛋白，LAO的基因。组氨酸转运操纵子的启动子已经从启动子上调突变dhuA 1的序列变化中鉴定出来。这两个调控区都不具有氨基酸生物合成操纵子调控区的任何典型特征，表明至少这些转运基因的调控不涉及转录衰减机制。我们已经确定了三个有趣的功能，目前在这两个序列，这可能是重要的，在这些和其他操纵子的调节：一个“茎环足”结构，一个特定的同源性区域，和镜像对称。镜像对称区域可能是一个蛋白质识别位点，重要的是调节这些和其他操纵子的表达，以响应氮的可用性。镜像对称作为DNA-蛋白质相互作用位点的结构以前没有被提出过。
We have determined the nucleotide sequences of the regulatory regions from two amino acid transport operons from Salmonella typhimurium: dhuA, which regulates the histidine transport operon, and argTr, which regulates argT, the gene encoding the lysine-arginine-ornithine-binding protein, LAO. The promoter for the histidine transport operon has been identified from the sequence change in the promoter-up mutation dhuA1. Neither regulatory region has any of the features typical of the regulatory regions of the amino acid biosynthetic operons, indicating that regulation of at least these transport genes does not involve a transcription attenuation mechanism. We have identified three interesting features, present in both of these sequences, which may be of importance in the regulation of these and other operons: a "stem-loop-foot" structure, a region of specific homology, and a mirror symmetry. The region of mirror symmetry may be a protein recognition site important is regulating expression of these and other operons in response to nitrogen availability. Mirror symmetry as a structure for DNA-protein interaction sites has not been proposed previously.