Structural view of the Ran-Importin beta interaction at 2.3 A resolution

Cell. 1999 May 28;97(5):635-46. doi: 10.1016/s0092-8674(00)80774-6.


Transport receptors of the Importin beta family shuttle between the nucleus and cytoplasm and mediate transport of macromolecules through nuclear pore complexes. They interact specifically with the GTP-binding protein Ran, which in turn regulates their interaction with cargo. Here, we report the three-dimensional structure of a complex between Ran bound to the nonhydrolyzable GTP analog GppNHp and a 462-residue fragment from Importin beta. The structure of Importin beta shows 10 tandem repeats resembling HEAT and Armadillo motifs. They form an irregular crescent, the concave site of which forms the interface with Ran-triphosphate. The importin-binding site of Ran does not overlap with that of the Ran-binding domain of RanBP2.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Binding Sites
  • Consensus Sequence
  • Crystallography, X-Ray
  • Drosophila
  • GTP-Binding Proteins / chemistry
  • GTP-Binding Proteins / metabolism
  • Guanylyl Imidodiphosphate / metabolism
  • Humans
  • Karyopherins
  • Models, Molecular
  • Molecular Sequence Data
  • Nuclear Proteins / chemistry*
  • Nuclear Proteins / metabolism
  • Oryza
  • Protein Isoforms / chemistry
  • Protein Isoforms / metabolism
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / metabolism
  • Saccharomyces cerevisiae
  • Schizosaccharomyces
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • ran GTP-Binding Protein


  • Karyopherins
  • Nuclear Proteins
  • Protein Isoforms
  • Recombinant Proteins
  • Guanylyl Imidodiphosphate
  • GTP-Binding Proteins
  • ran GTP-Binding Protein

Associated data

  • PDB/1IBR