Sinorhizobium fredii NGR234 Transcriptome or Gene expression. Sinorhizobium fredii NGR234

In this work we characterized the two-component signal transductions systems CrbS/R and RpuS/R from Sinorhizobium fredii NGR234. CrbS/R is needed for growth on acetate and is homologous to previously characterized proteins from Pseudomonas while RpuS/R, is a novel system required for optimal growth on pyruvate. Next, using RNAseq and transcriptional fusions we determined that this system up-regulates the expression of an operon coding for the pyruvate symporter MctP when pyruvate is the sole carbon source in S. fredii and identified a conserved DNA motif in the putative promoter region of the mctP operon that is essential for the RpuR-mediated transcriptional activation of genes under pyruvate-utilizing conditions.