THE RcsB-DEPENDENT MOTILITY BEHAVIOR REQUIRES THE LONG AND SHORT O-ANTIGEN CHAIN LENGTH DETERMINANTS

JUAN VICENTE FARIZANO; MARIA FLORENCIA BALLESTEROS; MARÍA DE LAS MERCEDES PESCARETTI; MÓNICA A. DELGADO

Córdoba, Argentina

Congreso; LII Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2016

THE RcsB-DEPENDENT MOTILITY BEHAVIOR REQUIRES THE LONG AND SHORT O-ANTIGEN CHAIN LENGTH DETERMINANTSFarizano JV, Ballesteros F,Pescaretti MM, Delgado MA. INSIBIO (CONICET-UNT) and Instituto de Qca Bca ?Dr. Bernabe Bloj? (UNT). Tucumán, Argentina. E-mail: merpescaretti@hotmail.comThe RcsCDB phosphorelay is an adaptive response system composed of three proteins: the sensor RcsC, the response regulator RcsB, and the histidin-containing phosphotransfer RcsD, which also can serve as a sensor. This system modulates the flagella and colanic acid biosynthesis operons and many virulence genes expression. In previous studies we demonstrated that wzzst gene is required for the enhanced swarming behavior displayed by the rcsB mutant. Our goal was investigate the relation between the O-antigen (Oag) length and the bacteria motility, when the flagella biosynthesis is under or not the control of RcsCDB. Here, we determined the swimming motility of wild type strain; rcsB, wzzst, wzzfepE, pbgE2 and pbgE3 mutants and wzzst rcsB and wzzfepE rcsB, pbgE2 rcsB and pbgE3 rcsB double mutants. It is important to remark that in S. Typhimurium the Oag follows a trimodal length distribution where WzzfepE controls the very long region, Wzzst the long and PbgE2 and PbgE3 the short part. We also studied the flhC gene expression in the above backgrounds in order to correlate the motility phenotype and the flagella expression. Finally, we analyzed the number and correct assembly of flagella in each analyzed strains, by electron microscopy. Our results demonstrate that the only long and short Oag chain length determinants are involves in the motility behavior controlled by RcsCDB system.