X-ray structures of ferritins and related proteins.
Ferritins are members of a much larger superfamily of proteins, which are characterised by a structural motif consisting of a bundle of four parallel and anti-parallel alpha helices. The ferritin superfamily itself is widely distributed across all three living kingdoms, in both aerobic and anaerobic organisms, and a considerable number of X-ray structures are available, some at extremely high resolution. We describe first of all the subunit structure of mammalian H and L chain ferritins and then discuss intersubunit interactions in the 24-subunit quaternary structure of these ferritins. Bacteria contain two types of ferritins, FTNs, which like mammalian ferritins do not contain haem, and the haem-containing BFRs. The characteristic carboxylate-bridged di-iron ferroxidase sites of H chain ferritins, FTNs and BFRs are compared, as are the potential entry sites for iron and the 'nucleation' site of L chain ferritins. Finally we discuss the three-dimensional structures of the 12-subunit bacterial Dps (DNA-binding protein from starved cells) proteins as well as their intersubunit di-iron ferroxidase site.
Crichton
Robert R
RR
Department of Chemistry, Université Catholique de Louvain, Louvain-la-Neuve, Belgium. Robert.crichton@uclouvain.be
Declercq
Jean-Paul
JP
D000818:Animals; D001052:Apoferritins / Q000737:chemistry; D018360:Crystallography, X-Ray / Q000379:methods; D005293:Ferritins / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D033862:Iron-Binding Proteins / Q000737:chemistry*; D008954:Models, Biological; D008958:Models, Molecular; D011487:Protein Conformation; D055503:Protein Multimerization / Q000502:physiology; D021122:Protein Subunits / Q000737:chemistry; D017385:Sequence Homology
D033862:Iron-Binding Proteins; D021122:Protein Subunits; D005293:Ferritins; D001052:Apoferritins