CATABOLITE REPRESSION-RESISTANT MUTATIONS OF THE BACILLUS-SUBTILIS ALPHA-AMYLASE PROMOTER AFFECT TRANSCRIPTION LEVELS AND ARE IN AN OPERATOR-LIKE SEQUENCE
CATABOLITE REPRESSION-RESISTANT MUTATIONS OF THE BACILLUS-SUBTILIS ALPHA-AMYLASE PROMOTER AFFECT TRANSCRIPTION LEVELS AND ARE IN AN OPERATOR-LIKE SEQUENCE
复制标题
DOI：
10.1016/0022-2836(87)90204-x
复制
发表时间：
1987-12-20
影响因子：
5.6
通讯作者：
CHAMBLISS, GH
中科院分区：
文献类型：
--
作者：
NICHOLSON, WL;PARK, YK;CHAMBLISS, GH
amyR 1基因座控制amyE的调节转录，amyE是枯草芽孢杆菌中编码α-淀粉酶的结构基因。amyE的转录在早期稳定期细胞中被激活，并且可以被快速代谢的碳源如葡萄糖抑制。amyE的转录在体外从由RNA聚合酶的主要营养形式E σ 43识别的启动子开始。体内淀粉酶转录物的S1核酸酶图谱表明该启动子也在体内使用。两个独立分离的顺式作用突变，gra-5和gra-10，这消除了葡萄糖介导的抑制淀粉酶的合成，而不改变时间的激活，通过DNA测序确定从G. cntdot。C到A. cntdot. T转换位于转录起始位点下游5个碱基对的位置。虽然这是革兰氏阳性微生物中参与基因表达的分解代谢产物抑制的位点的第一个例子，但围绕gra突变的区域与大肠杆菌中的某些顺式作用调控位点显示出相当大的同源性，这表明这些序列在进化上是保守的。
The amyR1 locus controls the regulated transcription of amyE, the structural gene encoding alpha-amylase in Bacillus subtilis. Transcription of amyE is activated in early stationary phase cells, and can be repressed by rapidly metabolized carbon sources such as glucose. Transcription of amyE initiates in vitro from a promoter recognized by the major vegetative form of RNA polymerase, E.sigma.43 . S1 nuclease mapping of in vivo amylase transcripts suggests that this promoter is also used in vivo. Two independently isolated cis-acting mutations, gra-5 and gra-10, which abolish glucose-mediated repression of amylase synthesis without altering temporal activation, were determined by DNA sequencing to result from a G .cntdot. C to A .cntdot. T transition at a position located five base-pairs downstream from the start site of transcription. While this is the first example of a site involved in catabolite repression of gene expression in a Gram-positive micro-organism, the region surrounding the gra mutations shows considerable homology to certain cis-acting regulatory loci in Escherichia coli, suggesting that such sequences have been evolutionarily conserved.