Structure of human ferritin L chain

Acta Crystallogr D Biol Crystallogr. 2006 Jul;62(Pt 7):800-6. doi: 10.1107/S0907444906018294. Epub 2006 Jun 20.

Abstract

Ferritin is the major iron-storage protein present in all cells. It generally contains 24 subunits, with different ratios of heavy chain (H) to light chain (L), in the shape of a hollow sphere hosting up to 4500 ferric Fe atoms inside. H-rich ferritins catalyse the oxidation of iron(II), while L-rich ferritins promote the nucleation and storage of iron(III). Several X-ray structures have been determined, including those of L-chain ferritins from horse spleen (HoSF), recombinant L-chain ferritins from horse (HoLF), mouse (MoLF) and bullfrog (BfLF) as well as recombinant human H-chain ferritin (HuHF). Here, structures have been determined of two crystal forms of recombinant human L-chain ferritin (HuLF) obtained from native and perdeuterated proteins. The structures show a cluster of acidic residues at the ferrihydrite nucleation site and at the iron channel along the threefold axis. An ordered Cd2+ structure is observed within the iron channel, offering further insight into the route and mechanism of iron transport into the capsid. The loop between helices D and E, which is disordered in many other L-chain structures, is clearly visible in these two structures. The crystals generated from perdeuterated HuLF will be used for neutron diffraction studies.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acids / chemistry
  • Amino Acids / metabolism
  • Animals
  • Binding Sites
  • Cadmium / chemistry
  • Cadmium / metabolism
  • Crystallography, X-Ray
  • Ferritins / chemistry*
  • Ferritins / genetics
  • Ferritins / metabolism
  • Ferrous Compounds / chemistry
  • Ferrous Compounds / metabolism
  • Horses / metabolism
  • Humans
  • Iron / chemistry
  • Iron / metabolism
  • Models, Molecular
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Protein Subunits / chemistry
  • Protein Subunits / genetics
  • Protein Subunits / metabolism
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / metabolism
  • Water / chemistry

Substances

  • Amino Acids
  • Ferrous Compounds
  • Protein Subunits
  • Recombinant Proteins
  • Cadmium
  • Water
  • Ferritins
  • Iron