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| | ==Crystal structure of human Importin-beta (127-876) in complex with the IBB-domain of Snurportin1 (1-65)== | | ==Crystal structure of human Importin-beta (127-876) in complex with the IBB-domain of Snurportin1 (1-65)== |
| - | <StructureSection load='2qna' size='340' side='right' caption='[[2qna]], [[Resolution|resolution]] 2.84Å' scene=''> | + | <StructureSection load='2qna' size='340' side='right'caption='[[2qna]], [[Resolution|resolution]] 2.84Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[2qna]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2QNA OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2QNA FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[2qna]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2QNA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2QNA FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr> | + | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">KPNB1, NTF97 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN]), SNUPN, RNUT1, SPN1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN])</td></tr> | + | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">KPNB1, NTF97 ([https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN]), SNUPN, RNUT1, SPN1 ([https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN])</td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2qna FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2qna OCA], [http://pdbe.org/2qna PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2qna RCSB], [http://www.ebi.ac.uk/pdbsum/2qna PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=2qna ProSAT]</span></td></tr> | + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=2qna FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2qna OCA], [https://pdbe.org/2qna PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2qna RCSB], [https://www.ebi.ac.uk/pdbsum/2qna PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2qna ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/IMB1_HUMAN IMB1_HUMAN]] Functions in nuclear protein import, either in association with an adapter protein, like an importin-alpha subunit, which binds to nuclear localization signals (NLS) in cargo substrates, or by acting as autonomous nuclear transport receptor. Acting autonomously, serves itself as NLS receptor. Docking of the importin/substrate complex to the nuclear pore complex (NPC) is mediated by KPNB1 through binding to nucleoporin FxFG repeats and the complex is subsequently translocated through the pore by an energy requiring, Ran-dependent mechanism. At the nucleoplasmic side of the NPC, Ran binds to importin-beta and the three components separate and importin-alpha and -beta are re-exported from the nucleus to the cytoplasm where GTP hydrolysis releases Ran from importin. The directionality of nuclear import is thought to be conferred by an asymmetric distribution of the GTP- and GDP-bound forms of Ran between the cytoplasm and nucleus. Mediates autonomously the nuclear import of ribosomal proteins RPL23A, RPS7 and RPL5. Binds to a beta-like import receptor binding (BIB) domain of RPL23A. In association with IPO7 mediates the nuclear import of H1 histone. In vitro, mediates nuclear import of H2A, H2B, H3 and H4 histones. In case of HIV-1 infection, binds and mediates the nuclear import of HIV-1 Rev. Imports PRKCI into the nucleus.<ref>PMID:9687515</ref> <ref>PMID:10228156</ref> <ref>PMID:11891849</ref> [[http://www.uniprot.org/uniprot/SPN1_HUMAN SPN1_HUMAN]] Functions as an U snRNP-specific nuclear import adapter. Involved in the trimethylguanosine (m3G)-cap-dependent nuclear import of U snRNPs. Binds specifically to the terminal m3G-cap U snRNAs.<ref>PMID:9670026</ref> | + | [[https://www.uniprot.org/uniprot/IMB1_HUMAN IMB1_HUMAN]] Functions in nuclear protein import, either in association with an adapter protein, like an importin-alpha subunit, which binds to nuclear localization signals (NLS) in cargo substrates, or by acting as autonomous nuclear transport receptor. Acting autonomously, serves itself as NLS receptor. Docking of the importin/substrate complex to the nuclear pore complex (NPC) is mediated by KPNB1 through binding to nucleoporin FxFG repeats and the complex is subsequently translocated through the pore by an energy requiring, Ran-dependent mechanism. At the nucleoplasmic side of the NPC, Ran binds to importin-beta and the three components separate and importin-alpha and -beta are re-exported from the nucleus to the cytoplasm where GTP hydrolysis releases Ran from importin. The directionality of nuclear import is thought to be conferred by an asymmetric distribution of the GTP- and GDP-bound forms of Ran between the cytoplasm and nucleus. Mediates autonomously the nuclear import of ribosomal proteins RPL23A, RPS7 and RPL5. Binds to a beta-like import receptor binding (BIB) domain of RPL23A. In association with IPO7 mediates the nuclear import of H1 histone. In vitro, mediates nuclear import of H2A, H2B, H3 and H4 histones. In case of HIV-1 infection, binds and mediates the nuclear import of HIV-1 Rev. Imports PRKCI into the nucleus.<ref>PMID:9687515</ref> <ref>PMID:10228156</ref> <ref>PMID:11891849</ref> [[https://www.uniprot.org/uniprot/SPN1_HUMAN SPN1_HUMAN]] Functions as an U snRNP-specific nuclear import adapter. Involved in the trimethylguanosine (m3G)-cap-dependent nuclear import of U snRNPs. Binds specifically to the terminal m3G-cap U snRNAs.<ref>PMID:9670026</ref> |
| | == Evolutionary Conservation == | | == Evolutionary Conservation == |
| | [[Image:Consurf_key_small.gif|200px|right]] | | [[Image:Consurf_key_small.gif|200px|right]] |
| | Check<jmol> | | Check<jmol> |
| | <jmolCheckbox> | | <jmolCheckbox> |
| - | <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/qn/2qna_consurf.spt"</scriptWhenChecked> | + | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/qn/2qna_consurf.spt"</scriptWhenChecked> |
| | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> |
| | <text>to colour the structure by Evolutionary Conservation</text> | | <text>to colour the structure by Evolutionary Conservation</text> |
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| | </div> | | </div> |
| | <div class="pdbe-citations 2qna" style="background-color:#fffaf0;"></div> | | <div class="pdbe-citations 2qna" style="background-color:#fffaf0;"></div> |
| | + | |
| | + | ==See Also== |
| | + | *[[Importin 3D structures|Importin 3D structures]] |
| | == References == | | == References == |
| | <references/> | | <references/> |
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| | </StructureSection> | | </StructureSection> |
| | [[Category: Human]] | | [[Category: Human]] |
| | + | [[Category: Large Structures]] |
| | [[Category: Dickmanns, A]] | | [[Category: Dickmanns, A]] |
| | [[Category: Ficner, R]] | | [[Category: Ficner, R]] |
| Structural highlights
Function
[IMB1_HUMAN] Functions in nuclear protein import, either in association with an adapter protein, like an importin-alpha subunit, which binds to nuclear localization signals (NLS) in cargo substrates, or by acting as autonomous nuclear transport receptor. Acting autonomously, serves itself as NLS receptor. Docking of the importin/substrate complex to the nuclear pore complex (NPC) is mediated by KPNB1 through binding to nucleoporin FxFG repeats and the complex is subsequently translocated through the pore by an energy requiring, Ran-dependent mechanism. At the nucleoplasmic side of the NPC, Ran binds to importin-beta and the three components separate and importin-alpha and -beta are re-exported from the nucleus to the cytoplasm where GTP hydrolysis releases Ran from importin. The directionality of nuclear import is thought to be conferred by an asymmetric distribution of the GTP- and GDP-bound forms of Ran between the cytoplasm and nucleus. Mediates autonomously the nuclear import of ribosomal proteins RPL23A, RPS7 and RPL5. Binds to a beta-like import receptor binding (BIB) domain of RPL23A. In association with IPO7 mediates the nuclear import of H1 histone. In vitro, mediates nuclear import of H2A, H2B, H3 and H4 histones. In case of HIV-1 infection, binds and mediates the nuclear import of HIV-1 Rev. Imports PRKCI into the nucleus.[1] [2] [3] [SPN1_HUMAN] Functions as an U snRNP-specific nuclear import adapter. Involved in the trimethylguanosine (m3G)-cap-dependent nuclear import of U snRNPs. Binds specifically to the terminal m3G-cap U snRNAs.[4]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The nuclear import of assembled spliceosomal subunits, the uridine-rich small nuclear ribonucleoprotein particles (U snRNPs), is mediated by a nuclear import receptor adaptor couple of importin beta (Imp beta) and snurportin1 (SPN1). In contrast to any other characterized active nuclear import, the Imp beta/SPN1/U snRNP complex does not require RanGTP for the terminal release from the nuclear basket of the nuclear pore complex (NPC). The crystal structure of Imp beta (127-876) in complex with the Imp beta-binding (IBB) domain of SPN1 (1-65) at 2.8-A resolution reveals that Imp beta adopts an open conformation, which is unique for a functional Imp beta/cargo complex, and rather surprisingly, it resembles the conformation of the Imp beta/RanGTP complex. As binding of RanGTP to Imp beta usually triggers the release of import complexes from the NPC, we propose that by already mimicking a conformation similar to Imp beta/RanGTP the independent dissociation of Imp beta/SPN1 from the nuclear basket is energetically aided.
Structural basis for RanGTP independent entry of spliceosomal U snRNPs into the nucleus.,Wohlwend D, Strasser A, Dickmanns A, Ficner R J Mol Biol. 2007 Dec 7;374(4):1129-38. Epub 2007 Sep 29. PMID:18028944[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Jakel S, Gorlich D. Importin beta, transportin, RanBP5 and RanBP7 mediate nuclear import of ribosomal proteins in mammalian cells. EMBO J. 1998 Aug 3;17(15):4491-502. PMID:9687515 doi:10.1093/emboj/17.15.4491
- ↑ Jakel S, Albig W, Kutay U, Bischoff FR, Schwamborn K, Doenecke D, Gorlich D. The importin beta/importin 7 heterodimer is a functional nuclear import receptor for histone H1. EMBO J. 1999 May 4;18(9):2411-23. PMID:10228156 doi:10.1093/emboj/18.9.2411
- ↑ White WO, Seibenhener ML, Wooten MW. Phosphorylation of tyrosine 256 facilitates nuclear import of atypical protein kinase C. J Cell Biochem. 2002;85(1):42-53. PMID:11891849
- ↑ Huber J, Cronshagen U, Kadokura M, Marshallsay C, Wada T, Sekine M, Luhrmann R. Snurportin1, an m3G-cap-specific nuclear import receptor with a novel domain structure. EMBO J. 1998 Jul 15;17(14):4114-26. PMID:9670026 doi:10.1093/emboj/17.14.4114
- ↑ Wohlwend D, Strasser A, Dickmanns A, Ficner R. Structural basis for RanGTP independent entry of spliceosomal U snRNPs into the nucleus. J Mol Biol. 2007 Dec 7;374(4):1129-38. Epub 2007 Sep 29. PMID:18028944 doi:10.1016/j.jmb.2007.09.065
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