The mechanism of heme transfer from the cytoplasmic heme binding protein PhuS to the delta-regioselective heme oxygenase of Pseudomonas aeruginosa.

ABSTRACT: The opportunistic pathogen Pseudomonas aeruginosa has evolved two outer membrane receptor-mediated uptake systems (encoded by the phu and has operons) by which it can utilize the hosts heme and hemeproteins as a source of iron. PhuS is a cytoplasmic heme binding protein encoded within the phu operon and has previously been shown to function in the trafficking of heme to the iron-regulated heme oxygenase (pa-HO). While the heme association rate for PhuS was similar to that of myoglobin, a markedly higher rate of heme dissociation (approximately 10(5) s(-1)) was observed, in keeping with a function in heme-trafficking. Additionally, the transfer of heme from PhuS to pa-HO was shown to be specific and unidirectional when compared to transfer to the non-iron regulated heme oxygenase (BphO), in

SUBMITTER: Bhakta MN 

PROVIDER: S-EPMC2631378 | biostudies-literature | 2006 Sep

REPOSITORIES: biostudies-literature