9BTS

Crystal structure of the bacterioferritin (Bfr) and ferritin (Ftn) heterooligomer complex from Acinetobacter baumannii

Summary for 9BTS

• Entry DOI: 10.2210/pdb9bts/pdb
• Descriptor: Bacterioferritin (Bfr), Ferritin (Ftn), SULFATE ION, ... (5 entities in total)
• Functional Keywords: electron transport, iron storage, iron binding, iron mobilization, heterooligomer, acinetobacter baumannii, oxidoreductase
• Biological source: Acinetobacter baumannii ATCC 17978; More
• Total number of polymer chains: 16
• Total formula weight: 293563.87

Authors

Lovell, S.,Liu, L.,Battaile, K.P.,Rivera, M. (deposition date: 2024-05-15, release date: 2024-08-14, Last modification date: 2024-08-21)

Primary citation

Yao, H.,Alli, S.,Liu, L.,Soldano, A.,Cooper, A.,Fontenot, L.,Verdin, D.,Battaile, K.P.,Lovell, S.,Rivera, M.
The crystal structure of Acinetobacter baumannii bacterioferritin reveals a heteropolymer of bacterioferritin and ferritin subunits.
Sci Rep, 14:18242-18242, 2024

PubMed Abstract: Iron storage proteins, e.g., vertebrate ferritin, and the ferritin-like bacterioferritin (Bfr) and bacterial ferritin (Ftn), are spherical, hollow proteins that catalyze the oxidation of Fe at binuclear iron ferroxidase centers (FOC) and store the Fe in their interior, thus protecting cells from unwanted Fe/Fe redox cycling and storing iron at concentrations far above the solubility of Fe. Vertebrate ferritins are heteropolymers of H and L subunits with only the H subunits having FOC. Bfr and Ftn were thought to coexist in bacteria as homopolymers, but recent evidence indicates these molecules are heteropolymers assembled from Bfr and Ftn subunits. Despite the heteropolymeric nature of vertebrate and bacterial ferritins, structures have been determined only for recombinant proteins constituted by a single subunit type. Herein we report the structure of Acinetobacter baumannii bacterioferritin, the first structural example of a heteropolymeric ferritin or ferritin-like molecule, assembled from completely overlapping Ftn homodimers harboring FOC and Bfr homodimers devoid of FOC but binding heme. The Ftn homodimers function by catalyzing the oxidation of Fe to Fe, while the Bfr homodimers bind a cognate ferredoxin (Bfd) which reduces the stored Fe by transferring electrons via the heme, enabling Fe mobilization to the cytosol for incorporation in metabolism.

PubMed: 39107474
DOI: 10.1038/s41598-024-69156-2

Experimental method

X-RAY DIFFRACTION (1.85 Å)