Evaluation and characterization of catabolite-responsive elements (cre) of Bacillus subtilis
Evaluation and characterization of catabolite-responsive elements (cre) of Bacillus subtilis
复制标题
DOI：
10.1093/nar/28.5.1206
复制
发表时间：
2000-03-01
影响因子：
14.9
通讯作者：
Fujita, Y
中科院分区：
文献类型：
--
作者：
Miwa, Y;Nakata, A;Fujita, Y
芽孢杆菌属的分解代谢物阻遏的全局机制包括通过CcpA蛋白与靶基因的分解代谢物响应元件（克雷斯）的结合而施加的负调节。我们使用查询序列WTGNAANCGNWNNCW（N和W分别代表任何碱基和A或T）搜索枯草芽孢杆菌基因组中的提示序列，挑选出126个推定的和已知的提示序列。为了检查它们的提示功能，我们将spec启动子（Pspac）-cre-lacZ融合物整合到amyE基因座中。对整合体中β-半乳糖苷酶合成的分解代谢产物抑制的研究使我们得出以下结论：（i）提示序列与查询序列的低错配是它们发挥功能所必需的;（ii）尽管提示序列是部分回文的，但与靶基因转录方向相同的低错配比相反方向的低错配对它们的功能更重要;以及（iii）然而，为了更好的功能，需要更多回文性质的提示序列。此外，22个在体内起作用的线索的比对涉及共有序列WWTGNAARCGNWWWCAWW（R代表a或A）。有趣的是，在提示序列位于靶基因的蛋白质编码区的情况下，它们的保守碱基优先是允许碱基简并的密码子的第三个碱基。
A global mechanism of catabolite repression of the genus Bacillus comprises negative regulation exerted through the binding of the CcpA protein to the catabolite-responsive elements (cres) of the target genes. We searched for cue sequences in the Bacillus subtilis genome using a query sequence, WTGNAANCGNWNNCW (N and W stand for any base and A or T, respectively), picking out 126 putative and known cue sequences, To examine their cue function, we integrated spec promoter (Pspac)-cre-lacZ fusions into the amyE locus. Examination of catabolite repression of beta-galactosidase synthesis in the integrants led us to the following conclusions: (i) lower mismatching of cue sequences to the query sequence is required for their function; (ii) although cue sequences are partially palindromic, low mismatching in the same direction as that of transcription of the target genes is more critical for their function than that in the inverse direction; and (iii) yet, a more palindromic nature of cue sequences is desirable for a better function. Furthermore, the alignment of 22 cues that function in vivo implicated a consensus sequence, WWTGNAARCGNWWWCAWW (R stands for a or A). Interestingly, in the case where cue sequences are located in the protein-coding regions of the target genes, their conserved bases are preferentially the third bases of codons where base degeneracy is allowed.