RT Journal Article SR Electronic(1) A1 Pescaretti, María de las Mercedes A1 López, Fabián E. A1 Morero, Roberto D. A1 Delgado, Mónica A.YR 2010 T1 Transcriptional autoregulation of the RcsCDB phosphorelay system in Salmonella enterica serovar Typhimurium JF Microbiology, VO 156 IS 12 SP 3513 OP 3521 DO https://doi.org/10.1099/mic.0.041319-0 PB Microbiology Society, SN 1465-2080, AB The RcsCDB (Rcs) phosphorelay system is involved in the regulation of many envelope genes, such as those responsible for capsule synthesis, flagella production and O-antigen chain length, as well as in other cellular activities of several enteric bacteria. The system is composed of three proteins: the sensor RcsC, the response regulator RcsB, and the phospho-transfer intermediary protein RcsD. Previously, we reported two important aspects of this system: (a) rcsB gene expression is under the control of P rcsDB and P rcsB promoters, and (b) rcsD gene transcription decreases when the bacteria reach high levels of the RcsB regulator. In the present work, we demonstrate that the RcsB protein represses rcsD gene expression by binding directly to the P rcsDB promoter, negatively autoregulating the Rcs system. Furthermore, we report the physiological role of the RcsB regulator, which is able to modify bacterial swarming behaviour when expressed under the control of the P rcsB promoter., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.041319-0