Inácio José Manuel, de Sá-Nogueira Isabel
Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Avenida da República, Apartado 127, 2781-901 Oeiras, Portugal.
J Bacteriol. 2007 Nov;189(22):8371-6. doi: 10.1128/JB.01217-07. Epub 2007 Sep 7.
In Bacillus subtilis, the synthesis of enzymes involved in the degradation of arabinose-containing polysaccharides is subject to carbon catabolite repression (CCR). Here we show that CcpA is the major regulator of repression of the arabinases genes in the presence of glucose. CcpA acts via binding to one cre each in the promoter regions of the abnA and xsa genes and to two cres in the araABDLMNPQ-abfA operon. The contributions of the coeffectors HPr and Crh to CCR differ according to growth phase. HPr dependency occurs during both exponential growth and the transitional phase, while Crh dependency is detected mainly at the transitional phase. Our results suggest that Crh synthesis may increase at the end of exponential growth and consequently contribute to this effect, together with other factors.
在枯草芽孢杆菌中，参与含阿拉伯糖多糖降解的酶的合成受到碳分解代谢物阻遏（CCR）的调控。在此我们表明，在葡萄糖存在的情况下，CcpA是阿拉伯糖苷酶基因阻遏的主要调节因子。CcpA通过分别与abnA和xsa基因启动子区域中的一个cre位点以及araABDLMNPQ - abfA操纵子中的两个cre位点结合来发挥作用。辅效应物HPr和Crh对CCR的贡献因生长阶段而异。在指数生长期和过渡阶段均出现对HPr的依赖性，而对Crh的依赖性主要在过渡阶段检测到。我们的结果表明，Crh的合成可能在指数生长期结束时增加，从而与其他因素一起促成这种效应。
