1qbk
From Proteopedia
(New page: 200px<br /> <applet load="1qbk" size="450" color="white" frame="true" align="right" spinBox="true" caption="1qbk, resolution 3.0Å" /> '''STRUCTURE OF THE KAR...) |
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| - | [[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== | ||
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==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== | ||
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[[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
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STRUCTURE OF THE KARYOPHERIN BETA2-RAN GPPNHP NUCLEAR TRANSPORT COMPLEX
Contents |
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 and 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
Categories: Homo sapiens | Protein complex | Blobel, G. | Chook, Y M. | GNP | MG | Heat repeats
