Abstract 3024 A heme-dependent conformational switch in the Pseudomonas aeruginosa PhuS protein drives its function from transcriptional regulator to heme chaperone

Pseudomonas aeruginosa an opportunistic pathogen requires iron for survival and virulence. Within the host heme is the preferred source of iron, particularly in chronic infection where P. aeruginosa switches to utilize heme at the expense of iron-siderophores. Heme enters the cell through two non-redundant heme uptake systems, the heme assimilation system (Has) and the Pseudomonas heme uptake (Phu) system. Once in the cytoplasm, heme is bound by PhuS, which selectively transfers heme to heme oxygenase (HemO) for metabolism and release of iron and the biliverdin (BVIX)beta and BVIXdelta metabolites.