The structural mechanism for iron uptake and release by transferrins.

摘要: Transferrins are a group of iron-binding proteins that control the levels iron in body fluids vertebrates by their ability to bind two Fe3+ and CO3 2-. The transferrin molecule, with molecular mass about 80 kDa, is folded into similarly sized homologous N- C-lobes stabilized many intrachain disulfides. As observed X-ray crystallography, each lobe further divided domains, domain 1 2, an Fe3+-binding site within interdomain cleft. Four six coordination sites occupied protein ligands (2 Tyr residues, Asp, His) other bidentate Upon uptake release Fe3+, transferrins undergo large-scale conformational change dependng on common structural mechanism: domains 2 rotate as rigid bodies around rotation axis passes through antiparallel β-strands linking domains. extent rotaion is, however, variable for different specie...