1qbk: Difference between revisions
New page: left|200px<br /> <applet load="1qbk" size="450" color="white" frame="true" align="right" spinBox="true" caption="1qbk, resolution 3.0Å" /> '''STRUCTURE OF THE KAR... |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:1qbk.gif|left|200px]]<br /> | [[Image:1qbk.gif|left|200px]]<br /><applet load="1qbk" size="350" color="white" frame="true" align="right" spinBox="true" | ||
<applet load="1qbk" size=" | |||
caption="1qbk, resolution 3.0Å" /> | caption="1qbk, resolution 3.0Å" /> | ||
'''STRUCTURE OF THE KARYOPHERIN BETA2-RAN GPPNHP NUCLEAR TRANSPORT COMPLEX'''<br /> | '''STRUCTURE OF THE KARYOPHERIN BETA2-RAN GPPNHP NUCLEAR TRANSPORT COMPLEX'''<br /> | ||
==Overview== | ==Overview== | ||
Transport factors in the karyopherin-beta (also called importin-beta) | Transport factors in the karyopherin-beta (also called importin-beta) family mediate the movement of macromolecules in nuclear-cytoplasmic transport pathways. Karyopherin-beta2 (transportin) binds a cognate import substrate and targets it to the nuclear pore complex. In the nucleus, Ran x GTP binds karyopherin-beta2 and dissociates the substrate. Here we present the 3.0 A structure of the karyopherin-beta2-Ran x GppNHp complex where GppNHp is a non-hydrolysable GTP analogue. Karyopherin-beta2 contains eighteen HEAT repeats arranged into two continuous orthogonal arches. Ran is clamped in the amino-terminal arch and substrate-binding activity is mapped to the carboxy-terminal arch. A large loop in HEAT repeat 7 spans both arches. Interactions of the loop with Ran and the C-terminal arch implicate it in GTPase-mediated dissociation of the import-substrate. Ran x GppNHp in the complex shows extensive structural rearrangement, compared to Ran GDP, in regions contacting karyopherin-beta2. This provides a structural basis for the specificity of the karyopherin-beta family for the GTP-bound state of Ran, as well as a rationale for interactions of the karyopherin-Ran complex with the regulatory proteins ranGAP, ranGEF and ranBP1. | ||
==Disease== | ==Disease== | ||
| Line 11: | Line 10: | ||
==About this Structure== | ==About this Structure== | ||
1QBK is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with MG and GNP as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | 1QBK is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=MG:'>MG</scene> and <scene name='pdbligand=GNP:'>GNP</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QBK OCA]. | ||
==Reference== | ==Reference== | ||
| Line 18: | Line 17: | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
[[Category: Blobel, G.]] | [[Category: Blobel, G.]] | ||
[[Category: Chook, Y | [[Category: Chook, Y M.]] | ||
[[Category: GNP]] | [[Category: GNP]] | ||
[[Category: MG]] | [[Category: MG]] | ||
[[Category: heat repeats]] | [[Category: heat repeats]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:37:58 2008'' | ||
Revision as of 12:37, 21 February 2008
|
STRUCTURE OF THE KARYOPHERIN BETA2-RAN GPPNHP NUCLEAR TRANSPORT COMPLEX
Overview
Transport factors in the karyopherin-beta (also called importin-beta) family mediate the movement of macromolecules in nuclear-cytoplasmic transport pathways. Karyopherin-beta2 (transportin) binds a cognate import substrate and targets it to the nuclear pore complex. In the nucleus, Ran x GTP binds karyopherin-beta2 and dissociates the substrate. Here we present the 3.0 A structure of the karyopherin-beta2-Ran x GppNHp complex where GppNHp is a non-hydrolysable GTP analogue. Karyopherin-beta2 contains eighteen HEAT repeats arranged into two continuous orthogonal arches. Ran is clamped in the amino-terminal arch and substrate-binding activity is mapped to the carboxy-terminal arch. A large loop in HEAT repeat 7 spans both arches. Interactions of the loop with Ran and the C-terminal arch implicate it in GTPase-mediated dissociation of the import-substrate. Ran x GppNHp in the complex shows extensive structural rearrangement, compared to Ran GDP, in regions contacting karyopherin-beta2. This provides a structural basis for the specificity of the karyopherin-beta family for the GTP-bound state of Ran, as well as a rationale for interactions of the karyopherin-Ran complex with the regulatory proteins ranGAP, ranGEF and ranBP1.
Disease
Known diseases associated with this structure: Deafness, mitochondrial, modifier of OMIM:[610230], Osteolysis, familial expansile OMIM:[603499], Paget disease of bone OMIM:[603499]
About this Structure
1QBK is a Protein complex structure of sequences from Homo sapiens with MG and GNP as ligands. Full crystallographic information is available from OCA.
Reference
Structure of the nuclear transport complex karyopherin-beta2-Ran x GppNHp., Chook YM, Blobel G, Nature. 1999 May 20;399(6733):230-7. PMID:10353245
Page seeded by OCA on Thu Feb 21 14:37:58 2008
