2QMR

Karyopherin beta2/transportin

Summary for 2QMR

• Entry DOI: 10.2210/pdb2qmr/pdb
• Related: 1qbk 2h4m 2ot8
• Descriptor: Transportin-1 (1 entity in total)
• Functional Keywords: heat repeat, cytoplasm, host-virus interaction, nucleus, polymorphism, protein transport, transport, transport protein
• Biological source: Homo sapiens (human)
• Cellular location: Cytoplasm: Q92973
• Total number of polymer chains: 4
• Total formula weight: 405633.75

Authors

Cansizoglu, A.E.,Chook, Y.M. (deposition date: 2007-07-16, release date: 2007-10-30, Last modification date: 2023-08-30)

Primary citation

Cansizoglu, A.E.,Chook, Y.M.
Conformational heterogeneity of karyopherin beta2 is segmental
Structure, 15:1431-1441, 2007

PubMed Abstract: Karyopherinbeta2 (Kap beta2) or transportin imports numerous RNA binding proteins into the nucleus. Kap beta2 binds substrates in the cytoplasm and targets them through the nuclear pore complex, where RanGTP dissociates them in the nucleus. Here we report the 3.0 A crystal structure of unliganded Kap beta2, which consists of a superhelix of 20 HEAT repeats. Together with previously reported structures of NLS and Ran complexes, this structure provides understanding of conformational heterogeneity that accompanies ligand binding. The Kap beta2 superhelix is divided into three major segments. Two of them (HEAT repeats 9-13 and 14-18), which constitute the substrate binding site, are rigid elements that rotate relative to each other about a flexible hinge. The third (HEAT repeats 1-8), which constitutes the Ran binding site, exhibits conformational changes throughout its length. An analogous segmental architecture is also observed in Importin beta, suggesting that it is functionally significant and may be conserved in other import karyopherins.

PubMed: 17997969
DOI: 10.1016/j.str.2007.09.009

Experimental method

X-RAY DIFFRACTION (3 Å)