RcsB-dependent effects on nar operon regulation during the aerobic growth of Salmonella Typhimurium

TORRES LAMBERTI, MF; BALLESTEROS, MARÍA F.; LOPEZ, FE; PESCARETTI MM,; DELGADO M. A

BIOCHIMIE

ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER

Año: 2019

0300-9084

Abstrac24 t25 The intracellular pathogen Salmonella is an important cause of human foodborne diseases26 worldwide. Salmonella takes advantage of the phosphorelay regulatory systems to survive in the27 hostile environment of the host´s gastrointestinal tract. It has been reported that the nitrate28 reductase Z (NR-Z), encoded by the narUZYV operon, is required during Salmonella transition to29 anaerobic environments and is constitutively produced at low levels, but little is known about the30 regulatory mechanism involved in the operon gene expression. In this work, we found that the31 RcsCDB system is activated by high concentrations of specific sugars as a carbon source. In this32 activation state, the RcsCDB system participates in the negative control of narUZYWV33 expression. This control strategy occurs during exponential growth when the carbon source is34 high, allowing for normal aerobic respiration. The RcsCDB system?s participation in aerobic35 respiration is necessary to ensure efficient metabolism and optimal energy consumption when the36 bacteria are growing exponentially.