1gcj
From Proteopedia
(New page: 200px<br /><applet load="1gcj" size="450" color="white" frame="true" align="right" spinBox="true" caption="1gcj, resolution 2.6Å" /> '''N-TERMINAL FRAGMENT O...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1gcj.gif|left|200px]]<br /><applet load="1gcj" size=" | + | [[Image:1gcj.gif|left|200px]]<br /><applet load="1gcj" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1gcj, resolution 2.6Å" /> | caption="1gcj, resolution 2.6Å" /> | ||
'''N-TERMINAL FRAGMENT OF IMPORTIN-BETA'''<br /> | '''N-TERMINAL FRAGMENT OF IMPORTIN-BETA'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Importin-beta is a nuclear transport factor which mediates the nuclear | + | Importin-beta is a nuclear transport factor which mediates the nuclear import of various nuclear proteins. The N-terminal 1-449 residue fragment of mouse importin-beta (impbeta449) possesses the ability to bidirectionally translocate through the nuclear pore complex (NPC), and to bind RanGTP. The structure of the uncomplexed form of impbeta449 has been solved at a 2.6 A resolution by X-ray crystallography. It consists of ten copies of the tandemly arrayed HEAT repeat and exhibits conformational flexibility which is involved in protein-protein interaction for nuclear transport. The overall conformation of the HEAT repeats shows that a twisted motion produces a significantly varied superhelical architecture from the previously reported structure of RanGTP-bound importin-beta. These conformational changes appear to be the sum of small conformational changes throughout the polypeptide. Such a flexibility, which resides in the stacked HEAT repeats, is essential for interaction with RanGTP or with NPCs. Furthermore, it was found that impbeta449 has a structural similarity with another nuclear migrating protein, namely beta-catenin, which is composed of another type of helix-repeated structure of ARM repeat. Interestingly, the essential regions for NPC translocation for both importin-beta and beta-catenin are spatially well overlapped with one another. This strongly indicates the importance of helix stacking of the HEAT or ARM repeats for NPC-passage. |
==About this Structure== | ==About this Structure== | ||
| - | 1GCJ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Full crystallographic information is available from [http:// | + | 1GCJ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1GCJ OCA]. |
==Reference== | ==Reference== | ||
| Line 17: | Line 17: | ||
[[Category: Kose, S.]] | [[Category: Kose, S.]] | ||
[[Category: Kumasaka, T.]] | [[Category: Kumasaka, T.]] | ||
| - | [[Category: Lee, S | + | [[Category: Lee, S J.]] |
[[Category: Nakagawa, A.]] | [[Category: Nakagawa, A.]] | ||
[[Category: Sakai, H.]] | [[Category: Sakai, H.]] | ||
| Line 27: | Line 27: | ||
[[Category: nuclear pore-targeting complex component]] | [[Category: nuclear pore-targeting complex component]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:48:38 2008'' |
Revision as of 10:48, 21 February 2008
|
N-TERMINAL FRAGMENT OF IMPORTIN-BETA
Overview
Importin-beta is a nuclear transport factor which mediates the nuclear import of various nuclear proteins. The N-terminal 1-449 residue fragment of mouse importin-beta (impbeta449) possesses the ability to bidirectionally translocate through the nuclear pore complex (NPC), and to bind RanGTP. The structure of the uncomplexed form of impbeta449 has been solved at a 2.6 A resolution by X-ray crystallography. It consists of ten copies of the tandemly arrayed HEAT repeat and exhibits conformational flexibility which is involved in protein-protein interaction for nuclear transport. The overall conformation of the HEAT repeats shows that a twisted motion produces a significantly varied superhelical architecture from the previously reported structure of RanGTP-bound importin-beta. These conformational changes appear to be the sum of small conformational changes throughout the polypeptide. Such a flexibility, which resides in the stacked HEAT repeats, is essential for interaction with RanGTP or with NPCs. Furthermore, it was found that impbeta449 has a structural similarity with another nuclear migrating protein, namely beta-catenin, which is composed of another type of helix-repeated structure of ARM repeat. Interestingly, the essential regions for NPC translocation for both importin-beta and beta-catenin are spatially well overlapped with one another. This strongly indicates the importance of helix stacking of the HEAT or ARM repeats for NPC-passage.
About this Structure
1GCJ is a Single protein structure of sequence from Mus musculus. Full crystallographic information is available from OCA.
Reference
The adoption of a twisted structure of importin-beta is essential for the protein-protein interaction required for nuclear transport., Lee SJ, Imamoto N, Sakai H, Nakagawa A, Kose S, Koike M, Yamamoto M, Kumasaka T, Yoneda Y, Tsukihara T, J Mol Biol. 2000 Sep 8;302(1):251-64. PMID:10964573
Page seeded by OCA on Thu Feb 21 12:48:38 2008
