Structural Basis and Mechanism of a Unique Haemophore in the Haem-Iron Acquisition by Riemerella anatipestifer.

ABSTRACT: Several bacterial pathogens employ haemophores to scavenge haem from host haemoprotein to obtain an iron source. However, no homologues of well-characterized haemophores are found in Riemerella anatipestifer, a bacterium belonging to the order Flavobacteriales that encodes haem uptake systems. Herein, a unique haemophore RhuH is characterized in this bacterium. R. anatipestifer used RhuH to grow when duck hemoglobin serves as the sole iron resource. RhuH is secreted as a component of outer membrane vesicles. Recombinant RhuH exhibited a high binding affinity for haem (K_d of 3.44 × 10^-11 m) and can extract haem from duck hemoglobin. X-ray crystallography elucidated the 3D structure of RhuH at 2.85 Å resolution, showing a dimeric conformation with each monomer exhibitin

SUBMITTER: Wang M 

PROVIDER: S-EPMC11967795 | biostudies-literature | 2025 Apr

REPOSITORIES: biostudies-literature