2IU2

Recombinant human H ferritin, K86Q, E27D and E107D mutant, soaked with Zn ions

Summary for 2IU2

• Entry DOI: 10.2210/pdb2iu2/pdb
• Related: 2CEI 2CHI 2CIH 2CLU 2CN6 2CN7
• Descriptor: FERRITIN HEAVY CHAIN, ZINC ION, GLYCEROL, ... (4 entities in total)
• Functional Keywords: oxidoreductase, iron, apoferritin, ferroxidase, iron storage, metal-binding, phosphorylation, di-iron non-heme protein
• Biological source: HOMO SAPIENS (HUMAN)
• Total number of polymer chains: 1
• Total formula weight: 21711.10

Authors

Toussaint, L.,Crichton, R.R.,Declercq, J.P. (deposition date: 2006-05-26, release date: 2006-12-13, Last modification date: 2023-12-13)

Primary citation

Toussaint, L.,Bertrand, L.,Hue, L.,Crichton, R.R.,Declercq, J.P.
High-Resolution X-Ray Structures of Human Apoferritin H-Chain Mutants Correlated with Their Activity and Metal-Binding Sites.
J.Mol.Biol., 365:440-, 2007

PubMed Abstract: Ferritins are a family of proteins distributed widely in nature. In bacterial, plant, and animal cells, ferritin appears to serve as a soluble, bioavailable, and non-toxic form of iron provider. Ferritins from animal sources are heteropolymers composed of two types of subunit, H and L, which differ mainly by the presence (H) or absence (L) of active ferroxidase centres. We report the crystallographic structures of four human H apoferritin variants at a resolution of up to 1.5 Angstrom. Crystal derivatives using Zn(II) as redox-stable alternative for Fe(II), allows us to characterize the different metal-binding sites. The ferroxidase centre, which is composed of sites A and B, binds metal with a preference for the A site. In addition, distinct Zn(II)-binding sites were found in the 3-fold axes, 4-fold axes and on the cavity surface near the ferroxidase centre. To study the importance of the distance of the two metal atoms in the ferroxidase centre, single and double replacement of glutamate 27 (site A) and glutamate 107 (site B), the two axial ligands, by aspartate residues have been carried out. The consequences for metal binding and the correlation with Fe(II) oxidation rates are discussed.

PubMed: 17070541
DOI: 10.1016/J.JMB.2006.10.010

Experimental method

X-RAY DIFFRACTION (1.8 Å)