title: Dealing with iron: common structural principles in proteins that transport iron and heme.
abstract: Iron is essential to life, but poses severe problems because of its toxicity and the insolubility of hydrated ferric ions at neutral pH. In animals, a family of proteins called transferrins are responsible for the sequestration, transport, and distribution of free iron. Comparison of the structure and function of transferrins with a completely unrelated protein hemopexin, which carries out the same function for heme, identifies molecular features that contribute to a successful protein system for iron acquisition, transport, and release. These include a two-domain protein structure with flexible hinges that allow these domains to enclose the bound ligand and provide suitable chemistry for stable binding and an appropriate trigger for release.
authors.affiliation: School of Biological Sciences and Department of Chemistry, University of Auckland, Private Bag 92-019, Auckland, New Zealand.
authors.forename: Heather M
authors.initials: HM
authors.lastname: Baker
authors.forename: Bryan F
authors.initials: BF
authors.lastname: Anderson
authors.forename: Edward N
authors.initials: EN
authors.lastname: Baker
mesh_terms: D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism; D006418:Heme / Q000378:metabolism*; D006466:Hemopexin / Q000737:chemistry / Q000378:metabolism; D007501:Iron / Q000378:metabolism*; D008958:Models, Molecular; D017510:Protein Folding; D017433:Protein Structure, Secondary; D014168:Transferrin / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D014168:Transferrin; D006418:Heme; D006466:Hemopexin; D007501:Iron