The PmrA/PmrB regulatory system controls the expression of wzzfepE gene involved in the O-antigen synthesis of Salmonella enterica serovar Typhimurium

MARIA DE LAS MERCEDES PESCARETTI; FABIAN E. LOPEZ; ROBERTO MORERO; MONICA A. DELGADO

MICROBIOLOGY-UK

SOC GENERAL MICROBIOLOGY

Año: 2011 vol. 157 p. 2515 - 2521

1350-0872

The polimerization degree of O-antigen from Salmonella enterica serovar Typhimurium is controlled by the wzzst and wzzfepE genes products. In the present study we investigated the role of the PmrA/PmrB regulatory system on the wzzfepE gene transcription. We report that the direct binding of the PmrA regulator to a specific promoter site induces the expression of wzzfepE gene. This effect increases the amount of O-antigen very long region which is required for the resistance of Salmonella to serum human complement and polymyxin B, and for the bacteria replication within macrophages. The results obtained here highlight functional differences between WzzfepE and Wzzst, even when both genes are regulated by a PmrA-dependent way.