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| <SX load='6n89' size='340' side='right' viewer='molstar' caption='[[6n89]], [[Resolution|resolution]] 7.50Å' scene=''> | | <SX load='6n89' size='340' side='right' viewer='molstar' caption='[[6n89]], [[Resolution|resolution]] 7.50Å' scene=''> |
| == Structural highlights == | | == Structural highlights == |
| <table><tr><td colspan='2'>[[6n89]] 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=6N89 OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=6N89 FirstGlance]. <br> | | <table><tr><td colspan='2'>[[6n89]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6N89 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6N89 FirstGlance]. <br> |
| </td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[6n88|6n88]]</td></tr> | | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 7.5Å</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]), H1F0, H1FV ([http://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'>[https://proteopedia.org/fgij/fg.htm?mol=6n89 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6n89 OCA], [https://pdbe.org/6n89 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6n89 RCSB], [https://www.ebi.ac.uk/pdbsum/6n89 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6n89 ProSAT]</span></td></tr> |
| <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=6n89 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6n89 OCA], [http://pdbe.org/6n89 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6n89 RCSB], [http://www.ebi.ac.uk/pdbsum/6n89 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6n89 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/H10_HUMAN H10_HUMAN]] Histones H1 are necessary for the condensation of nucleosome chains into higher-order structures. The H1F0 histones are found in cells that are in terminal stages of differentiation or that have low rates of cell division. | | [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> |
| <div style="background-color:#fffaf0;">
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| == Publication Abstract from PubMed ==
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| Protein transport into the nucleus is mediated by transport receptors. Import of highly charged proteins, such as histone H1 and ribosomal proteins, requires a dimer of two transport receptors. In this study, we determined the cryo-EM structure of the Imp7:Impbeta:H1.0 complex, showing that the two importins form a cradle that accommodates the linker histone. The H1.0 globular domain is bound to Impbeta, whereas the acidic loops of Impbeta and Imp7 chaperone the positively charged C-terminal tail. Although it remains disordered, the H1 tail serves as a zipper that closes and stabilizes the structure through transient non-specific interactions with importins. Moreover, we found that the GGxxF and FxFG motifs in the Imp7 C-terminal tail are essential for Imp7:Impbeta dimerization and H1 import, resembling importin interaction with nucleoporins, which, in turn, promote complex disassembly. The architecture of many other complexes might be similarly defined by rapidly exchanging electrostatic interactions mediated by disordered regions.
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| Fuzzy Interactions Form and Shape the Histone Transport Complex.,Ivic N, Potocnjak M, Solis-Mezarino V, Herzog F, Bilokapic S, Halic M Mol Cell. 2019 Feb 15. pii: S1097-2765(19)30052-8. doi:, 10.1016/j.molcel.2019.01.032. PMID:30824373<ref>PMID:30824373</ref>
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| From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
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| </div>
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| <div class="pdbe-citations 6n89" style="background-color:#fffaf0;"></div>
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| ==See Also== | | ==See Also== |
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| __TOC__ | | __TOC__ |
| </SX> | | </SX> |
| [[Category: Human]] | | [[Category: Homo sapiens]] |
| [[Category: Large Structures]] | | [[Category: Large Structures]] |
| [[Category: Bilokapic, S]] | | [[Category: Bilokapic S]] |
| [[Category: Halic, M]] | | [[Category: Halic M]] |
| [[Category: Ivic, N]] | | [[Category: Ivic N]] |
| [[Category: Disordered interaction]]
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| [[Category: Histone h1]]
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| [[Category: Imp7:impb:h1 0]]
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| [[Category: Importin]]
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| [[Category: Nuclear import]]
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| [[Category: Transport protein]]
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