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| | ==Structural basis of the flanking zinc-finger motifs crucial for the E3 ligase activity of the LNX1 RING domain== | | ==Structural basis of the flanking zinc-finger motifs crucial for the E3 ligase activity of the LNX1 RING domain== |
| - | <StructureSection load='5h7s' size='340' side='right' caption='[[5h7s]], [[Resolution|resolution]] 3.49Å' scene=''> | + | <StructureSection load='5h7s' size='340' side='right'caption='[[5h7s]], [[Resolution|resolution]] 3.49Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[5h7s]] is a 6 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=5H7S OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5H7S FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[5h7s]] is a 6 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=5H7S OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5H7S FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ZN:ZINC+ION'>ZN</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]] 3.49Å</td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[5h7r|5h7r]]</td></tr>
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">UBB ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN]), LNX1, LNX, PDZRN2, UNQ574/PRO1136 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN]), UBE2N, BLU ([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=5h7s FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5h7s OCA], [https://pdbe.org/5h7s PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5h7s RCSB], [https://www.ebi.ac.uk/pdbsum/5h7s PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5h7s ProSAT]</span></td></tr> |
| - | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/RING-type_E3_ubiquitin_transferase RING-type E3 ubiquitin transferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.3.2.27 2.3.2.27] </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=5h7s FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5h7s OCA], [http://pdbe.org/5h7s PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5h7s RCSB], [http://www.ebi.ac.uk/pdbsum/5h7s PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5h7s ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/UBB_HUMAN UBB_HUMAN]] Ubiquitin exists either covalently attached to another protein, or free (unanchored). When covalently bound, it is conjugated to target proteins via an isopeptide bond either as a monomer (monoubiquitin), a polymer linked via different Lys residues of the ubiquitin (polyubiquitin chains) or a linear polymer linked via the initiator Met of the ubiquitin (linear polyubiquitin chains). Polyubiquitin chains, when attached to a target protein, have different functions depending on the Lys residue of the ubiquitin that is linked: Lys-6-linked may be involved in DNA repair; Lys-11-linked is involved in ERAD (endoplasmic reticulum-associated degradation) and in cell-cycle regulation; Lys-29-linked is involved in lysosomal degradation; Lys-33-linked is involved in kinase modification; Lys-48-linked is involved in protein degradation via the proteasome; Lys-63-linked is involved in endocytosis, DNA-damage responses as well as in signaling processes leading to activation of the transcription factor NF-kappa-B. Linear polymer chains formed via attachment by the initiator Met lead to cell signaling. Ubiquitin is usually conjugated to Lys residues of target proteins, however, in rare cases, conjugation to Cys or Ser residues has been observed. When polyubiquitin is free (unanchored-polyubiquitin), it also has distinct roles, such as in activation of protein kinases, and in signaling.<ref>PMID:16543144</ref> <ref>PMID:19754430</ref> [[http://www.uniprot.org/uniprot/UBE2N_HUMAN UBE2N_HUMAN]] The UBE2V1-UBE2N and UBE2V2-UBE2N heterodimers catalyze the synthesis of non-canonical 'Lys-63'-linked polyubiquitin chains. This type of polyubiquitination does not lead to protein degradation by the proteasome. Mediates transcriptional activation of target genes. Plays a role in the control of progress through the cell cycle and differentiation. Plays a role in the error-free DNA repair pathway and contributes to the survival of cells after DNA damage. Acts together with the E3 ligases, HLTF and SHPRH, in the 'Lys-63'-linked poly-ubiquitination of PCNA upon genotoxic stress, which is required for DNA repair. Appears to act together with E3 ligase RNF5 in the 'Lys-63'-linked polyubiquitination of JKAMP thereby regulating JKAMP function by decreasing its association with components of the proteasome and ERAD. Promotes TRIM5 capsid-specific restriction activity and the UBE2V1-UBE2N heterodimer acts in concert with TRIM5 to generate 'Lys-63'-linked polyubiquitin chains which activate the MAP3K7/TAK1 complex which in turn results in the induction and expression of NF-kappa-B and MAPK-responsive inflammatory genes (By similarity).<ref>PMID:10089880</ref> <ref>PMID:14562038</ref> <ref>PMID:19269966</ref> <ref>PMID:20061386</ref> <ref>PMID:21512573</ref> [[http://www.uniprot.org/uniprot/LNX1_HUMAN LNX1_HUMAN]] E3 ubiquitin-protein ligase that mediates ubiquitination and subsequent proteasomal degradation of NUMB. E3 ubiquitin ligases accept ubiquitin from an E2 ubiquitin-conjugating enzyme in the form of a thioester and then directly transfers the ubiquitin to targeted substrates. Mediates ubiquitination of isoform p66 and isoform p72 of NUMB, but not that of isoform p71 or isoform p65 (By similarity). Isoform 2 provides an endocytic scaffold for IGSF5/JAM4 (By similarity). | + | [https://www.uniprot.org/uniprot/UBB_HUMAN UBB_HUMAN] Ubiquitin exists either covalently attached to another protein, or free (unanchored). When covalently bound, it is conjugated to target proteins via an isopeptide bond either as a monomer (monoubiquitin), a polymer linked via different Lys residues of the ubiquitin (polyubiquitin chains) or a linear polymer linked via the initiator Met of the ubiquitin (linear polyubiquitin chains). Polyubiquitin chains, when attached to a target protein, have different functions depending on the Lys residue of the ubiquitin that is linked: Lys-6-linked may be involved in DNA repair; Lys-11-linked is involved in ERAD (endoplasmic reticulum-associated degradation) and in cell-cycle regulation; Lys-29-linked is involved in lysosomal degradation; Lys-33-linked is involved in kinase modification; Lys-48-linked is involved in protein degradation via the proteasome; Lys-63-linked is involved in endocytosis, DNA-damage responses as well as in signaling processes leading to activation of the transcription factor NF-kappa-B. Linear polymer chains formed via attachment by the initiator Met lead to cell signaling. Ubiquitin is usually conjugated to Lys residues of target proteins, however, in rare cases, conjugation to Cys or Ser residues has been observed. When polyubiquitin is free (unanchored-polyubiquitin), it also has distinct roles, such as in activation of protein kinases, and in signaling.<ref>PMID:16543144</ref> <ref>PMID:19754430</ref> |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | </div> | | </div> |
| | <div class="pdbe-citations 5h7s" style="background-color:#fffaf0;"></div> | | <div class="pdbe-citations 5h7s" style="background-color:#fffaf0;"></div> |
| | + | |
| | + | ==See Also== |
| | + | *[[Ubiquitin protein ligase 3D structures|Ubiquitin protein ligase 3D structures]] |
| | == References == | | == References == |
| | <references/> | | <references/> |
| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Human]] | + | [[Category: Homo sapiens]] |
| - | [[Category: RING-type E3 ubiquitin transferase]] | + | [[Category: Large Structures]] |
| - | [[Category: Nayak, D]] | + | [[Category: Nayak D]] |
| - | [[Category: Sivaraman, J]] | + | [[Category: Sivaraman J]] |
| - | [[Category: E3 ligase]]
| + | |
| - | [[Category: Protein binding-ligase-transferase complex]]
| + | |
| - | [[Category: Ring]]
| + | |
| - | [[Category: Ubiquitin]]
| + | |
| - | [[Category: Zinc finger motif]]
| + | |
| Structural highlights
Function
UBB_HUMAN Ubiquitin exists either covalently attached to another protein, or free (unanchored). When covalently bound, it is conjugated to target proteins via an isopeptide bond either as a monomer (monoubiquitin), a polymer linked via different Lys residues of the ubiquitin (polyubiquitin chains) or a linear polymer linked via the initiator Met of the ubiquitin (linear polyubiquitin chains). Polyubiquitin chains, when attached to a target protein, have different functions depending on the Lys residue of the ubiquitin that is linked: Lys-6-linked may be involved in DNA repair; Lys-11-linked is involved in ERAD (endoplasmic reticulum-associated degradation) and in cell-cycle regulation; Lys-29-linked is involved in lysosomal degradation; Lys-33-linked is involved in kinase modification; Lys-48-linked is involved in protein degradation via the proteasome; Lys-63-linked is involved in endocytosis, DNA-damage responses as well as in signaling processes leading to activation of the transcription factor NF-kappa-B. Linear polymer chains formed via attachment by the initiator Met lead to cell signaling. Ubiquitin is usually conjugated to Lys residues of target proteins, however, in rare cases, conjugation to Cys or Ser residues has been observed. When polyubiquitin is free (unanchored-polyubiquitin), it also has distinct roles, such as in activation of protein kinases, and in signaling.[1] [2]
Publication Abstract from PubMed
LNX1 (Ligand of Numb Protein-X 1) is a RING and PDZ domain-containing E3 ubiquitin ligase that ubiquitinates human c-Src kinase. Here, we report the identification and structure of the ubiquitination domain of LNX1, the identification of Ubc13/Ube2V2 as a functional E2 in vitro, and the structural and functional studies of the Ubc13~Ub intermediate in complex with the ubiquitination domain of LNX1. The RING domain of LNX1 is embedded between two zinc-finger motifs (Zn-RING-Zn), both of which are crucial for its ubiquitination activity. In the heterodimeric complex, the ubiquitin of one monomer shares more buried surface area with LNX1 of the other monomer and these interactions are unique and essential for catalysis. This study reveals how the LNX1 RING domain is structurally and mechanistically dependent on other motifs for its E3 ligase activity, and describes how dimeric LNX1 recruits ubiquitin-loaded Ubc13 for Ub transfer via E3 ligase-mediated catalysis.
Structure of LNX1:Ubc13~Ubiquitin complex reveals the role of additional motifs for the E3 ligase activity of LNX1.,Nayak D, Sivaraman J J Mol Biol. 2018 Feb 26. pii: S0022-2836(18)30089-5. doi:, 10.1016/j.jmb.2018.02.016. PMID:29496391[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Huang F, Kirkpatrick D, Jiang X, Gygi S, Sorkin A. Differential regulation of EGF receptor internalization and degradation by multiubiquitination within the kinase domain. Mol Cell. 2006 Mar 17;21(6):737-48. PMID:16543144 doi:S1097-2765(06)00120-1
- ↑ Komander D. The emerging complexity of protein ubiquitination. Biochem Soc Trans. 2009 Oct;37(Pt 5):937-53. doi: 10.1042/BST0370937. PMID:19754430 doi:10.1042/BST0370937
- ↑ Nayak D, Sivaraman J. Structure of LNX1:Ubc13~Ubiquitin complex reveals the role of additional motifs for the E3 ligase activity of LNX1. J Mol Biol. 2018 Feb 26. pii: S0022-2836(18)30089-5. doi:, 10.1016/j.jmb.2018.02.016. PMID:29496391 doi:http://dx.doi.org/10.1016/j.jmb.2018.02.016
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