Activation pathway of the RcsC/YojN/RcsB regulatory system in Salmonella enterica

MARIA DE LAS MERCEDES PESCARETTI; ROBERTO MORERO; MÓNICA A. DELGADO

Rosario- Santa Fe (Argentina)

Congreso; XLII Annual Meeting of the Argentine Society for Biochemistry and Molecular Biology (SAIB); 2006

SAIB

The RcsC/YojN/RcsB phosphorelay system controls the expression of the extracellular polysaccharide colanic acid biosynthesis cps operon and the master flagellar regulator flhDC locus. The Rcs system consists of the sensor protein RcsC and its cognate response regulator RcsB as well as the histidin-containing phosphotransfer protein YojN that appears to serve as an intermediary in the phosphoryl transfer from RcsC to RcsB (Fig.1 A). Although numerous direct and indirect genetic and environmental factors are known to induce the Rcs System, the real signals that lead to activation of this system is unknown. We are interested in defining the signal that is sensed by RcsC and YojN proteins and determining whether of these two proteins can independently activate the RcsB regulator. In addition, we are defined that rcsB, located downstream of yojN, is expressed under two promoters: 1) the yojN promoter and 2) a new promoter located in the yojN N-terminal.