Kinetic and spectroscopic studies of hemin acquisition in the hemophore HasAp from Pseudomonas aeruginosa.

ABSTRACT: The extreme limitation of free iron has driven various pathogens to acquire iron from the host in the form of heme. Specifically, several Gram-negative pathogens secrete a heme binding protein known as HasA to scavenge heme from the extracellular environment and to transfer it to the receptor protein HasR for import into the bacterial cell. Structures of heme-bound and apo-HasA homologues show that the heme iron(III) ligands, His32 and Tyr75, reside on loops extending from the core of the protein and that a significant conformational change must occur at the His32 loop upon heme binding. Here, we investigate the kinetics of heme acquisition by HasA from Pseudomonas aeruginosa (HasAp). The rate of heme acquisition from human met-hemoglobin (met-Hb) closely matches that of heme dissociation

SUBMITTER: Yukl ET 

PROVIDER: S-EPMC2914800 | biostudies-literature | 2010 Aug

REPOSITORIES: biostudies-literature