4ZKH

Crystal structure of the PmFTN variant E44Q soaked in iron (overnight)

Summary for 4ZKH

• Entry DOI: 10.2210/pdb4zkh/pdb
• Related: 4ZKW 4ZKX 4ZL5 4ZL6
• Descriptor: Ferritin, FE (III) ION (3 entities in total)
• Functional Keywords: ferritin, di-iron ferroxidase centre, 4-helix bundle, oxidoreductase
• Biological source: Pseudo-nitzschia multiseries
• Total number of polymer chains: 8
• Total formula weight: 153452.23

Authors

Pfaffen, S.,Murphy, M.E.P. (deposition date: 2015-04-30, release date: 2015-09-30, Last modification date: 2023-09-27)

Primary citation

Pfaffen, S.,Bradley, J.M.,Abdulqadir, R.,Firme, M.R.,Moore, G.R.,Le Brun, N.E.,Murphy, M.E.
A Diatom Ferritin Optimized for Iron Oxidation but Not Iron Storage.
J.Biol.Chem., 290:28416-28427, 2015

PubMed Abstract: Ferritin from the marine pennate diatom Pseudo-nitzschia multiseries (PmFTN) plays a key role in sustaining growth in iron-limited ocean environments. The di-iron catalytic ferroxidase center of PmFTN (sites A and B) has a nearby third iron site (site C) in an arrangement typically observed in prokaryotic ferritins. Here we demonstrate that Glu-44, a site C ligand, and Glu-130, a residue that bridges iron bound at sites B and C, limit the rate of post-oxidation reorganization of iron coordination and the rate at which Fe(3+) exits the ferroxidase center for storage within the mineral core. The latter, in particular, severely limits the overall rate of iron mineralization. Thus, the diatom ferritin is optimized for initial Fe(2+) oxidation but not for mineralization, pointing to a role for this protein in buffering iron availability and facilitating iron-sparing rather than only long-term iron storage.

PubMed: 26396187
DOI: 10.1074/jbc.M115.669713

Experimental method

X-RAY DIFFRACTION (1.9 Å)