Protein Interaction of Rcs system components: a molecular understanding of structure¨Cfunction relationships in Salmonella typhimurium.

PESCARETTI MM,; LOPEZ, FE; MORERO RD,; DELGADO, MONICA ALEJANDRA

Salta-Argentina

Congreso; 3rd Latin American Protein Society Meeting; 2010

Latin American Protein Society

Protein Interaction of Rcs system components: a molecular understanding of structure¨Cfunction relationships in Salmonella typhimurium. Mar¨ªa de las Mercedes Pescaretti, Fabi¨¢n E. L¨®pez, Roberto Morero y M¨®nica A. Delgado. Departamento de Bioqu¨ªmica de la Nutrici¨®n, Instituto de Qu¨ªmica Biol¨®gica (CONICET-UNT), Chacabuco 461, 4000, Tucum¨¢n. merpescaretti@fbqf.unt.edu.ar. The Rcs regulatory system consists of three proteins: the sensor RcsC, the cognate response regulator RcsB; and the intermediary in the phosphoryl transfer RcsD. Those proteins are involved in complex multistep His-Asp-His-Asp phosphorlay pathways that act in the following order: RcsC¡úRcsD¡úRcsB, in which is possible that RcsC and RcsD interact to activate the RcsB regulator. The Rcs system has an important role in the bacterial physiology, controlling the capsule synthesis and motility behavior. Due to the relevant importance of this system, we have analyzed the interaction of the components in the Rcs network, at molecular levels. In this work we studied the structure of the different RcsC and RcsD domains by bioinformatics analysis. The in vivo bacterial two-hybrid assay (BACTH), allowed us to determine the potentials interactions between the Rcs components proteins, specifically the interaction of RcsC with the intermediary RcsD. In addition, the in vitro crosslinking assay was used to determine the ability of the RcsC and RcsD purified cytosolic domains to form dimmer/oligomers. The mechanism involved in the Rcs regulation circuit and the control of the physiological pathways remains to be elucidated.