The RcsB-dependent motility behavior requires the long and short o-antigen chain length determinants.

FARIZANO J. V; BALLESTEROS, MARIA FLORENCIA; PESCARETTI MM,; DELGADO, M. A.

Cordoba

Congreso; LII Reunión de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular (SAIB); 2016

SAIB

The 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 thatwzzstgene is required for the enhanced swarming behavior displayed by thercsBmutant. 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,pbgE2and pbgE3mutants andwzzstrcsBandwzzfepErcsB,pbgE2rcsB andpbgE3rcsBdouble mutants. It is important to remark that in S. Typhimurium the Oag follows a trimodal length distribution where WzzfepEcontrols the very long region, Wzzstthe long and PbgE2and PbgE3the short part. We also studied theflhCgene expressions 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 only the long and short Oag chain length determinants are involves in the motility behavior controlled by RcsCDB system.