| First Author | Forwood JK | Year | 2008 |
| Journal | J Mol Biol | Volume | 383 |
| Issue | 4 | Pages | 772-82 |
| PubMed ID | 18708071 | Mgi Jnum | J:168964 |
| Mgi Id | MGI:4939347 | Doi | 10.1016/j.jmb.2008.07.090 |
| Citation | Forwood JK, et al. (2008) Kap95p binding induces the switch loops of RanGDP to adopt the GTP-bound conformation: implications for nuclear import complex assembly dynamics. J Mol Biol 383(4):772-82 |
| abstractText | The asymmetric distribution of the nucleotide-bound state of Ran across the nuclear envelope is crucial for determining the directionality of nuclear transport. In the nucleus, Ran is primarily in the guanosine 5'-triphosphate (GTP)-bound state, whereas in the cytoplasm, Ran is primarily guanosine 5'-diphosphate (GDP)-bound. Conformational changes within the Ran switch I and switch II loops are thought to modulate its affinity for importin-beta. Here, we show that RanGDP and importin-beta form a stable complex with a micromolar dissociation constant. This complex can be dissociated by importin-beta binding partners such as importin-alpha. Surprisingly, the crystal structure of the Kap95p-RanGDP complex shows that Kap95p induces the switch I and II regions of RanGDP to adopt a conformation that resembles that of the GTP-bound form. The structure of the complex provides insights into the structural basis for the gradation of affinities regulating nuclear protein transport. |
