Plant pathogenic bacteria utilize biofilm growth-associated repressor (BigR), a novel winged-helix redox switch, to control hydrogen sulfide detoxification under hypoxia.

ABSTRACT: Winged-helix transcriptional factors play important roles in the control of gene expression in many organisms. In the plant pathogens Xylella fastidiosa and Agrobacterium tumefaciens, the winged-helix protein BigR, a member of the ArsR/SmtB family of metal sensors, regulates transcription of the bigR operon involved in bacterial biofilm growth. Previous studies showed that BigR represses transcription of its own operon through the occupation of the RNA polymerase-binding site; however, the signals that modulate its activity and the biological function of its operon are still poorly understood. Here we show that although BigR is a homodimer similar to metal sensors, it functions as a novel redox switch that derepresses transcription upon oxidation. Crystal structures of reduced and oxidized

SUBMITTER: Guimaraes BG 

PROVIDER: S-EPMC3138302 | biostudies-literature | 2011 Jul

REPOSITORIES: biostudies-literature