This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
1iq1
From Proteopedia
| Line 1: | Line 1: | ||
[[Image:1iq1.jpg|left|200px]] | [[Image:1iq1.jpg|left|200px]] | ||
| - | + | <!-- | |
| - | + | The line below this paragraph, containing "STRUCTURE_1iq1", creates the "Structure Box" on the page. | |
| - | + | You may change the PDB parameter (which sets the PDB file loaded into the applet) | |
| - | | | + | or the SCENE parameter (which sets the initial scene displayed when the page is loaded), |
| - | | | + | or leave the SCENE parameter empty for the default display. |
| - | + | --> | |
| - | + | {{STRUCTURE_1iq1| PDB=1iq1 | SCENE= }} | |
| - | + | ||
| - | + | ||
| - | }} | + | |
'''CRYSTAL STRUCTURE OF THE IMPORTIN-ALPHA(44-54)-IMPORTIN-ALPHA(70-529) COMPLEX''' | '''CRYSTAL STRUCTURE OF THE IMPORTIN-ALPHA(44-54)-IMPORTIN-ALPHA(70-529) COMPLEX''' | ||
| Line 30: | Line 27: | ||
[[Category: Kobe, B.]] | [[Category: Kobe, B.]] | ||
[[Category: Teh, T.]] | [[Category: Teh, T.]] | ||
| - | [[Category: | + | [[Category: Armadillo repeat]] |
| - | [[Category: | + | [[Category: Autoinhibition]] |
| - | [[Category: | + | [[Category: Solenoid]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 20:16:13 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 17:16, 2 May 2008
CRYSTAL STRUCTURE OF THE IMPORTIN-ALPHA(44-54)-IMPORTIN-ALPHA(70-529) COMPLEX
Overview
Proteins containing the classical nuclear localization sequences (NLSs) are imported into the nucleus by the importin-alpha/beta heterodimer. Importin-alpha contains the NLS binding site, whereas importin-beta mediates the translocation through the nuclear pore. We characterized the interactions involving importin-alpha during nuclear import using a combination of biophysical techniques (biosensor, crystallography, sedimentation equilibrium, electrophoresis, and circular dichroism). Importin-alpha is shown to exist in a monomeric autoinhibited state (association with NLSs undetectable by biosensor). Association with importin-beta (stoichiometry, 1:1; K(D) = 1.1 x 10(-8) m) increases the affinity for NLSs; the importin-alpha/beta complex binds representative monopartite NLS (simian virus 40 large T-antigen) and bipartite NLS (nucleoplasmin) with affinities (K(D) = 3.5 x 10(-8) m and 4.8 x 10(-8) m, respectively) comparable with those of a truncated importin-alpha lacking the autoinhibitory domain (T-antigen NLS, K(D) = 1.7 x 10(-8) m; nucleoplasmin NLS, K(D) = 1.4 x 10(-8) m). The autoinhibitory domain (as a separate peptide) binds the truncated importin-alpha, and the crystal structure of the complex resembles the structure of full-length importin-alpha. Our results support the model of regulation of nuclear import mediated by the intrasteric autoregulatory sequence of importin-alpha and provide a quantitative description of the binding and regulatory steps during nuclear import.
About this Structure
1IQ1 is a Protein complex structure of sequences from Mus musculus. Full crystallographic information is available from OCA.
Reference
Biophysical characterization of interactions involving importin-alpha during nuclear import., Catimel B, Teh T, Fontes MR, Jennings IG, Jans DA, Howlett GJ, Nice EC, Kobe B, J Biol Chem. 2001 Sep 7;276(36):34189-98. Epub 2001 Jul 11. PMID:11448961 Page seeded by OCA on Fri May 2 20:16:13 2008
