1fha: Difference between revisions

[[Image:1fha.gif|left|200px]]<br /><applet load="1fha" size="350" color="white" frame="true" align="right" spinBox="true"  

Ferritin is important in iron homeostasis. Its twenty-four chains of two types, H and L, assemble as a hollow shell providing an iron-storage cavity. Ferritin molecules in cells containing high levels of iron tend to be rich in L chains, and may have a long-term storage function, whereas H-rich ferritins are more active in iron metabolism. The molecular basis for the greater activity of H-rich ferritins has until now been obscure, largely because the structure of H-chain ferritin has remained unknown owing to the difficulties in obtaining crystals ordered enough for X-ray crystallographic analysis. Here we report the three-dimensional structure of a human ferritin H-chain homopolymer. By genetically engineering a change in the sequence of the intermolecular contact region, we obtained crystals isomorphous with the homologous rat L ferritin and of high enough quality for X-ray diffraction analysis. The X-ray structure of human H ferritin shows a novel metal site embedded within each of its four-helix bundles and we suggest that ferroxidase activity associated with this site accounts for its rapid uptake of iron.

1FHA is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=FE:'>FE</scene> and <scene name='pdbligand=CA:'>CA</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. The following page contains interesting information on the relation of 1FHA with [[http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb35_1.html Ferritin and Transferrin]]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1FHA OCA].  

[[Category: Artymiuk, P J.]]

[[Category: Harrison, P M.]]

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