1AEW: L-Chain Horse Apoferritin

Citation:
Abstract
Mammalian ferritins are 24-mers assembled from two types of polypeptide chain which provide the molecule with different functions. H(eavy) chains catalyse the first step in iron storage, the oxidation of iron(II). L(ight) chains promote the nucleation of the mineral ferrihydrite enabling storage of iron(III) inside the protein shell. We report here the comparison of the three-dimensional structures of recombinant human H chain (HuHF) and horse L chain (HoLF) ferritin homopolymers, which have been refined at 1.9 A resolution. There is 53% sequence identity between these molecules, and the two structures are very similar, the H and L subunit alpha-carbons superposing to within 0.5 A rms deviation with 41 water molecules in common. Nevertheless, there are significant important differences which can be related to differences in function. In particular, the centres of the four-helix bundles contain distinctive groups of hydrophilic residues which have been associated with ferroxidase activity in H chains and enhanced stability in L chains. L chains contain a group of glutamates associated with mineralisation within the iron storage cavity of the protein.
PDB ID: 1AEWDownload
MMDB ID: 55175
PDB Deposition Date: 1997/2/26
Updated in MMDB: 2012/11
Experimental Method:
x-ray diffraction
Resolution: 1.95  Å
Source Organism:
Similar Structures:
Biological Unit for 1AEW: 24-meric; determined by author and by software (PQS)
Molecular Components in 1AEW
Label Count Molecule
Proteins (24 molecules)
24
Ferritin(Gene symbol: FTL)
Molecule annotation
Chemicals (144 molecules)
1
144
* Click molecule labels to explore molecular sequence information.

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