Dealing with iron: common structural principles in proteins that transport iron and heme.
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.
Baker
Heather M
HM
School of Biological Sciences and Department of Chemistry, University of Auckland, Private Bag 92-019, Auckland, New Zealand.
Anderson
Bryan F
BF
Baker
Edward N
EN
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
D002352:Carrier Proteins; D014168:Transferrin; D006418:Heme; D006466:Hemopexin; D007501:Iron