RhuR, an extracytoplasmic function sigma factor activator, is essential for heme-dependent expression of the outer membrane heme and hemoprotein receptor of Bordetella avium.

ABSTRACT: Genes involved in iron (Fe) acquisition often are regulated in response to the local availability of Fe. In many bacteria, Fe-dependent responsiveness is mediated by Fur, a global Fe-dependent transcriptional repressor. Tighter regulatory control of Fur-responsive genes is afforded by incorporating additional regulators into Fur-dependent regulatory cascades. RhuI, a Fur-dependent extracytoplasmic function sigma factor of Bordetella avium, in response to the dual stimulation of Fe starvation and the presence of heme (or hemoproteins), regulates P(bhuR), a heme-responsive promoter which directs expression of the bhuRSTUV heme utilization operon. While BhuR, the outer membrane heme receptor, and RhuI have been shown to be indispensable for heme-dependent activation of P(bhuR), collateral com

SUBMITTER: Kirby AE 

PROVIDER: S-EPMC321627 | biostudies-literature | 2004 Feb

REPOSITORIES: biostudies-literature