| First Author | Cingolani G | Year | 1999 |
| Journal | Nature | Volume | 399 |
| Issue | 6733 | Pages | 221-9 |
| PubMed ID | 10353244 | Mgi Jnum | J:55037 |
| Mgi Id | MGI:1337162 | Doi | 10.1038/20367 |
| Citation | Cingolani G, et al. (1999) Structure of importin-beta bound to the IBB domain of importin-alpha [see comments]. Nature 399(6733):221-9 |
| abstractText | Cytosolic proteins bearing a classical nuclear localization signal enter the nucleus bound to a heterodimer of importin-alpha and importin-beta (also called karyopherin-alpha and -beta). The formation of this heterodimer involves the importin-beta-binding (IBB) domain of importin-alpha, a highly basic amino-terminal region of roughly 40 amino-acid residues. Here we report the crystal structure of human importin-beta bound to the IBB domain of importin-alpha, determined at 2.5 A and 2.3 A resolution in two crystal forms. Importin-beta consists of 19 tandemly repeated HEAT motifs and wraps intimately around the IBB domain. The association involves two separate regions of importin-beta, recognizing structurally distinct parts of the IBB domain: an amino-terminal extended moiety and a carboxy-terminal helix. The structure indicates that significant conformational changes occur when importin-beta binds or releases the IBB domain domain and suggests how dissociation of the importin-alpha/beta heterodimer may be achieved upon nuclear entry. |
