OVERLAPPING DIVERGENT PROMOTERS CONTROL EXPRESSION OF TN10 TETRACYCLINE RESISTANCE
OVERLAPPING DIVERGENT PROMOTERS CONTROL EXPRESSION OF TN10 TETRACYCLINE RESISTANCE
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DOI：
10.1016/0378-1119(83)90046-x
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发表时间：
1983-01-01
期刊：
影响因子：
3.5
通讯作者：
REZNIKOFF, WS
中科院分区：
文献类型：
--
作者：
BERTRAND, KP;POSTLE, K;REZNIKOFF, WS
先前研究了大肠杆菌K-12中转座子Tn 10四环素抗性决定簇的遗传组织和调控。tetA（Tn 10四环素抗性功能）和tetR（Tn 10泰特阻遏物）的结构基因从位于这2个结构基因之间的调节区中的启动子以相反方向转录。tetA和tetR的表达由四环素诱导。现在报道了Tn 10泰特调控区的DNA序列。tetA和tetR启动子在该区域内的位置通过体内泰特的5“末端的S1核酸酶作图来确定。tetA和tetR启动子重叠;转录起始点由36个碱基对分开。有人提出，2个类似的二分体对称的Tn 10泰特调控区域内的操作位点，在该泰特阻遏物结合到泰特DNA，抑制转录起始tetA和tetR启动子。Tn 10泰特调控区和pBR 322泰特调控区显示出显著的DNA序列同源性（53%）。
The genetic organization and regulation of the [transposon] Tn10 tetracycline-resistance determinant in Escherichia coli K-12 were previously examined. The structural genes for tetA, the Tn10 tetracycline-resistance function, and for tetR, the Tn10 tet repressor, are transcribed in opposite directions from promoters in a regulatory region located between the 2 structural genes. Expression of tetA and tetR is induced by tetracyline. The DNA sequence of the Tn10 tet regulatory region is now reported. The locations of the tetA and tetR promoters within this region were defined by S1 nuclease mapping of the 5'' ends of in vivo tet RNA. The tetA and tetR promoters overlap; the transcription start points are separated by 36 base pairs. It is proposed that 2 similar regions of dyad symmetry within the Tn10 tet regulatory region are operator sites at which tet repressor binds to tet DNA, inhibiting transcription initiation at the tetA and tetR promoters. The Tn10 tet regulatory region and the pBR322 tet regulatory region show significant DNA sequence homology (53%).