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| | <StructureSection load='5w4e' size='340' side='right'caption='[[5w4e]], [[Resolution|resolution]] 2.18Å' scene=''> | | <StructureSection load='5w4e' size='340' side='right'caption='[[5w4e]], [[Resolution|resolution]] 2.18Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[5w4e]] is a 3 chain structure with sequence from [http://en.wikipedia.org/wiki/Lk3_transgenic_mice Lk3 transgenic mice]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5W4E OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5W4E FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[5w4e]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Glaciozyma_antarctica Glaciozyma antarctica], [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [https://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5W4E OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5W4E FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.18Å</td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[5w4f|5w4f]], [[5w4g|5w4g]]</td></tr>
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</scene></td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">Kpna2, Rch1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=10090 LK3 transgenic mice])</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=5w4e FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5w4e OCA], [https://pdbe.org/5w4e PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5w4e RCSB], [https://www.ebi.ac.uk/pdbsum/5w4e PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5w4e ProSAT]</span></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=5w4e FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5w4e OCA], [http://pdbe.org/5w4e PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5w4e RCSB], [http://www.ebi.ac.uk/pdbsum/5w4e PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5w4e ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | + | == Function == |
| | + | [https://www.uniprot.org/uniprot/A0A2R2JFW7_9BASI A0A2R2JFW7_9BASI] [https://www.uniprot.org/uniprot/IMA1_MOUSE IMA1_MOUSE] Functions in nuclear protein import as an adapter protein for nuclear receptor KPNB1. Binds specifically and directly to substrates containing either a simple or bipartite NLS motif. 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. |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| | + | [[Category: Glaciozyma antarctica]] |
| | + | [[Category: Homo sapiens]] |
| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| - | [[Category: Lk3 transgenic mice]] | + | [[Category: Mus musculus]] |
| - | [[Category: London, R]] | + | [[Category: London R]] |
| - | [[Category: Pedersen, L C]] | + | [[Category: Pedersen LC]] |
| - | [[Category: Importin]]
| + | |
| - | [[Category: Nl]]
| + | |
| - | [[Category: Nuclear transport]]
| + | |
| - | [[Category: Protein binding]]
| + | |
| - | [[Category: Tdt]]
| + | |
| Structural highlights
Function
A0A2R2JFW7_9BASI IMA1_MOUSE Functions in nuclear protein import as an adapter protein for nuclear receptor KPNB1. Binds specifically and directly to substrates containing either a simple or bipartite NLS motif. 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.
Publication Abstract from PubMed
Despite the essential roles of pol X family enzymes in DNA repair, information about the structural basis of their nuclear import is limited. Recent studies revealed the unexpected presence of a functional nuclear localization signal (NLS) in DNA polymerase beta, indicating the importance of active nuclear targeting, even for enzymes likely to leak into and out of the nucleus. The current studies further explore the active nuclear transport of these enzymes by identifying and structurally characterizing the functional NLS sequences in the three remaining human pol X enzymes: terminal deoxynucleotidyl transferase (TdT), DNA polymerase mu (pol mu) and DNA polymerase lambda (pol lambda). NLS identifications are based on Importin alpha (Impalpha) binding affinity determined by fluorescence polarization of fluorescein-labeled NLS peptides, X-ray crystallographic analysis of the ImpalphaIBB*NLS complexes and fluorescence-based subcellular localization studies. All three polymerases use NLS sequences located near their N-terminus; TdT and pol mu utilize monopartite NLS sequences, while pol lambda utilizes a bipartite sequence, unique among the pol X family members. The pol mu NLS has relatively weak measured affinity for Impalpha, due in part to its proximity to the N-terminus that limits non-specific interactions of flanking residues preceding the NLS. However, this effect is partially mitigated by an N-terminal sequence unsupportive of Met1 removal by methionine aminopeptidase, leading to a 3-fold increase in affinity when the N-terminal methionine is present. Nuclear targeting is unique to each pol X family enzyme with variations dependent on the structure and unique functional role of each polymerase.
Variations in nuclear localization strategies among pol X family enzymes.,Kirby TW, Pedersen LC, Gabel SA, Gassman NR, London RE Traffic. 2018 Jun 22. doi: 10.1111/tra.12600. PMID:29931796[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Kirby TW, Pedersen LC, Gabel SA, Gassman NR, London RE. Variations in nuclear localization strategies among pol X family enzymes. Traffic. 2018 Jun 22. doi: 10.1111/tra.12600. PMID:29931796 doi:http://dx.doi.org/10.1111/tra.12600
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