4XKS

E. coli BFR variant Y45F

Summary for 4XKS

• Entry DOI: 10.2210/pdb4xks/pdb
• Descriptor: Bacterioferritin, SULFATE ION (3 entities in total)
• Functional Keywords: iron storage, diiron site, oxidoreductase
• Biological source: Escherichia coli K-12
• Total number of polymer chains: 12
• Total formula weight: 223176.95

Authors

Hemmings, A.M.,Le Brun, N.E.,Bradley, J.M. (deposition date: 2015-01-12, release date: 2015-12-16, Last modification date: 2024-01-10)

Primary citation

Bradley, J.M.,Svistunenko, D.A.,Lawson, T.L.,Hemmings, A.M.,Moore, G.R.,Le Brun, N.E.
Three Aromatic Residues are Required for Electron Transfer during Iron Mineralization in Bacterioferritin.
Angew.Chem.Int.Ed.Engl., 54:14763-14767, 2015

PubMed Abstract: Ferritins are iron storage proteins that overcome the problems of toxicity and poor bioavailability of iron by catalyzing iron oxidation and mineralization through the activity of a diiron ferroxidase site. Unlike in other ferritins, the oxidized di-Fe(3+) site of Escherichia coli bacterioferritin (EcBFR) is stable and therefore does not function as a conduit for the transfer of Fe(3+) into the storage cavity, but instead acts as a true catalytic cofactor that cycles its oxidation state while driving Fe(2+) oxidation in the cavity. Herein, we demonstrate that EcBFR mineralization depends on three aromatic residues near the diiron site, Tyr25, Tyr58, and Trp133, and that a transient radical is formed on Tyr25. The data indicate that the aromatic residues, together with a previously identified inner surface iron site, promote mineralization by ensuring the simultaneous delivery of two electrons, derived from Fe(2+) oxidation in the BFR cavity, to the di-ferric catalytic site for safe reduction of O2.

PubMed: 26474305
DOI: 10.1002/anie.201507486

Experimental method

X-RAY DIFFRACTION (1.57 Å)