Institute of Microbiology and Biotechnology, University of Ulm, Germany.
J Biotechnol. 2011 Jul 10;154(2-3):126-39. doi: 10.1016/j.jbiotec.2010.07.001. Epub 2010 Jul 8.
In Corynebacterium glutamicum, the transcriptional regulators of acetate metabolism RamA (encoded by cg2831) and RamB (encoded by cg0444) play an important role in expression control of genes involved in acetate and ethanol metabolism. Both regulators were speculated to have broader significance in expression control of further genes in the central metabolism of C. glutamicum. Here we investigated the RamA and RamB regulons by genome-wide transcriptome analysis with special emphasis on genes encoding enzymes of the central carbon metabolism. When compared to the parental wild-type, 253 genes and 81 genes showed different mRNA levels in defined RamA- and RamB-deficient C. glutamicum strains, respectively. Among these were genes involved in sugar uptake, glycolysis, gluconeogenesis, acetate, l-lactate or ethanol metabolism. The direct interaction of RamA and RamB proteins with the respective promoter/operator fragments was demonstrated in vitro by electrophoretic mobility shift assays. Taken together, we present evidence for an important role of RamA and RamB in global gene expression control in C. glutamicum.
在谷氨酸棒杆菌中，参与乙酸代谢的转录调控因子 RamA（由 cg2831 编码）和 RamB（由 cg0444 编码）在参与乙酸和乙醇代谢的基因表达调控中发挥着重要作用。这两个调控因子被推测在谷氨酸棒杆菌中心代谢中进一步基因的表达调控中具有更广泛的意义。在这里，我们通过全基因组转录组分析研究了 RamA 和 RamB 调控子，特别强调了编码中心碳代谢酶的基因。与亲本野生型相比，在定义的 RamA 和 RamB 缺陷型谷氨酸棒杆菌菌株中，分别有 253 个基因和 81 个基因的 mRNA 水平存在差异。其中包括参与糖摄取、糖酵解、糖异生、乙酸、l-乳酸或乙醇代谢的基因。通过电泳迁移率变动分析在体外证明了 RamA 和 RamB 蛋白与各自启动子/操纵子片段的直接相互作用。综上所述，我们为 RamA 和 RamB 在谷氨酸棒杆菌的全局基因表达调控中发挥重要作用提供了证据。
