Molecular basis of hemoglobin binding and heme removal in <i>Corynebacterium diphtheriae</i>.

ABSTRACT: To successfully mount infections, nearly all bacterial pathogens must acquire iron, a key metal cofactor that primarily resides within human hemoglobin. Corynebacterium diphtheriae causes the life-threatening respiratory disease diphtheria and captures hemoglobin for iron scavenging using the surface-displayed receptor HbpA. Here, we show using X-ray crystallography, NMR, and in situ binding measurements that C. diphtheriae selectively captures iron-loaded hemoglobin by partially ensconcing the heme molecules of its α subunits. Quantitative growth and heme release measurements are compatible with C. diphtheriae acquiring heme passively released from hemoglobin's β subunits. We propose a model in which HbpA and heme-binding receptors collectively function on the C. d

SUBMITTER: Mahoney BJ 

PROVIDER: S-EPMC11725911 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature