The heme-regulatory motifs of heme oxygenase-2 contribute to the transfer of heme to the catalytic site for degradation.

ABSTRACT: Heme-regulatory motifs (HRMs) are present in many proteins that are involved in diverse biological functions. The C-terminal tail region of human heme oxygenase-2 (HO2) contains two HRMs whose cysteine residues form a disulfide bond; when reduced, these cysteines are available to bind Fe³⁺-heme. Heme binding to the HRMs occurs independently of the HO2 catalytic active site in the core of the protein, where heme binds with high affinity and is degraded to biliverdin. Here, we describe the reversible, protein-mediated transfer of heme between the HRMs and the HO2 core. Using hydrogen-deuterium exchange (HDX)-MS to monitor the dynamics of HO2 with and without Fe³⁺-heme bound to the HRMs and to the core, we detected conformational changes in the catalytic core only in one

SUBMITTER: Fleischhacker AS 

PROVIDER: S-EPMC7170523 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature