Structure-function analyses reveal key features in Staphylococcus aureus IsdB-associated unfolding of the heme-binding pocket of human hemoglobin.

ABSTRACT: IsdB is a receptor on the surface of the bacterial pathogen Staphylococcus aureus that extracts heme from hemoglobin (Hb) to enable growth on Hb as a sole iron source. IsdB is critically important both for in vitro growth on Hb and in infection models and is also highly up-regulated in blood, serum, and tissue infection models, indicating a key role of this receptor in bacterial virulence. However, structural information for IsdB is limited. We present here a crystal structure of a complex between human Hb and IsdB. In this complex, the α subunits of Hb are refolded with the heme displaced to the interface with IsdB. We also observe that atypical residues of Hb, His⁵⁸ and His⁸⁹ of αHb, coordinate to the heme iron, which is poised for transfer into the he

SUBMITTER: Bowden CFM 

PROVIDER: S-EPMC5766928 | biostudies-literature | 2018 Jan

REPOSITORIES: biostudies-literature