The Pseudomonas aeruginosa PhuS proximal ligand His-209 triggers a conformational switch in function from DNA binding to heme transfer.

ABSTRACT: Pseudomonas aeruginosa can acquire iron from heme via the heme assimilation system and Pseudomonas heme uptake (Phu) systems. Heme uptake is regulated at the metabolic level by the cytoplasmic protein PhuS that controls heme flux through a heme oxygenase HemO, releasing iron and biliverdin IXβ and IXδ. We have shown PhuS regulates extracellular heme flux, and in its apo-form transcriptionally regulates the iron and heme-dependent small RNAs (sRNAs) PrrF/PrrH. This mutual exclusivity of function is driven by conformational rearrangement of PhuS on heme binding. Herein, we show through a combination of EMSA and fluorescence anisotropy that mutation of the His-209 proximal ligand allows both apo- and holo-PhuS H209A to bind to the prrF1 promoter with significantly lower affinity when compared

SUBMITTER: Montes N 

PROVIDER: S-EPMC12033910 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature