Site-directed mutagenesis of a catabolite repression operator sequence in Bacillus subtilis.
Site-directed mutagenesis of a catabolite repression operator sequence in Bacillus subtilis.
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DOI：
10.1073/pnas.87.16.6238
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发表时间：
1990-08
影响因子：
11.1
通讯作者：
M. Weickert;G. Chambliss
中科院分区：
文献类型：
--
作者：
M. Weickert;G. Chambliss
枯草芽孢杆菌α -淀粉酶基因（amyE）的分解代谢物抑制涉及一个位于启动子（amyR）下游的操作符序列，重叠转录起始位点。该序列的寡核苷酸定点突变鉴定了分解代谢抑制所需的碱基。两个突变增加了算子的2倍对称性和抑制比。虽然许多突变使抑制比降低了3- 11倍，但有些突变也使淀粉酶产量增加了2倍或更多。另一些则引起高产而不影响分解代谢抑制。在其他抑制分解代谢物的枯草芽孢杆菌启动子中的同源序列表明一个共同的调控位点可能参与分解代谢物的抑制。
Catabolite repression of the Bacillus subtilis alpha-amylase gene (amyE) involves an operator sequence located just downstream of the promoter (amyR), overlapping the transcription start site. Oligonucleotide site-directed mutagenesis of this sequence identified bases required for catabolite repression. Two mutations increased both the 2-fold symmetry of the operator and the repression ratio. Although many mutations reduced the repression ratio 3- to 11-fold, some also caused a 2-fold or greater increase in amylase production. Others caused hyperproduction without affecting catabolite repression. Homologous sequences in other catabolite-repressed B. subtilis promoters suggest a common regulatory site may be involved in catabolite repression.