4r62
From Proteopedia
(Difference between revisions)
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| - | ''' | + | ==Structure of Rad6~Ub== |
| + | <StructureSection load='4r62' size='340' side='right' caption='[[4r62]], [[Resolution|resolution]] 2.28Å' scene=''> | ||
| + | == Structural highlights == | ||
| + | <table><tr><td colspan='2'>[[4r62]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4R62 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4R62 FirstGlance]. <br> | ||
| + | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene></td></tr> | ||
| + | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4qwh|4qwh]]</td></tr> | ||
| + | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Ubiquitin--protein_ligase Ubiquitin--protein ligase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.3.2.19 6.3.2.19] </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=4r62 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4r62 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4r62 RCSB], [http://www.ebi.ac.uk/pdbsum/4r62 PDBsum]</span></td></tr> | ||
| + | </table> | ||
| + | == Function == | ||
| + | [[http://www.uniprot.org/uniprot/UBC2_YEAST UBC2_YEAST]] Catalyzes the covalent attachment of ubiquitin to other proteins. In association with the E3 enzyme BRE1 and LGE1, it plays a role in transcription regulation by catalyzing the monoubiquitination of histone H2B to form H2BK123ub1. H2BK123ub1 gives a specific tag for epigenetic transcriptional activation, elongation by RNA polymerase II, telomeric silencing, and is also a prerequisite for H3K4me and H3K79me formation. In association with the E3 enzyme RAD18, it catalyzes the monoubiquitination of POL30 'Lys-164', involved in postreplication repair of UV-damaged DNA. The RAD6/UBC2-RAD18 complex is also involved in prevention of spontaneous mutations caused by 7,8-dihydro-8-oxoguanine. In association with the E3 enzyme UBR1, is involved in N-end rule-dependent protein degradation. Also involved in sporulation.<ref>PMID:3306404</ref> <ref>PMID:7038392</ref> <ref>PMID:2157209</ref> <ref>PMID:1651502</ref> <ref>PMID:2065660</ref> <ref>PMID:8436296</ref> <ref>PMID:7926769</ref> <ref>PMID:9287349</ref> <ref>PMID:9343433</ref> <ref>PMID:10880451</ref> <ref>PMID:12077605</ref> <ref>PMID:12226657</ref> <ref>PMID:14752010</ref> <ref>PMID:15388802</ref> <ref>PMID:16307922</ref> <ref>PMID:15632065</ref> <ref>PMID:16247017</ref> [[http://www.uniprot.org/uniprot/RS27A_HUMAN RS27A_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> Ribosomal protein S27a is a component of the 40S subunit of the ribosome.<ref>PMID:16543144</ref> <ref>PMID:19754430</ref> | ||
| + | <div style="background-color:#fffaf0;"> | ||
| + | == Publication Abstract from PubMed == | ||
| + | Rad6 is a yeast E2 ubiquitin conjugating enzyme that monoubiquitinates histone H2B in conjunction with the E3, Bre1, but can non-specifically modify histones on its own. We determined the crystal structure of a Rad6 approximately Ub thioester mimic, which revealed a network of interactions in the crystal in which the ubiquitin in one conjugate contacts Rad6 in another. The region of Rad6 contacted is located on the distal face of Rad6 opposite the active site, but differs from the canonical E2 backside that mediates free ubiquitin binding and polyubiquitination activity in other E2 enzymes. We find that free ubiquitin interacts weakly with both non-canonical and canonical backside residues of Rad6 and that mutations of non-canonical residues have deleterious effects on Rad6 activity comparable to those observed to mutations in the canonical E2 backside. The effect of non-canonical backside mutations is similar in the presence and absence of Bre1, indicating that contacts with non-canonical backside residues govern the intrinsic activity of Rad6. Our findings shed light on the determinants of intrinsic Rad6 activity and reveal new ways in which contacts with an E2 backside can regulate ubiquitin conjugating activity. | ||
| - | + | Role of a non-canonical surface of Rad6 in ubiquitin conjugating activity.,Kumar P, Magala P, Geiger-Schuller KR, Majumdar A, Tolman JR, Wolberger C Nucleic Acids Res. 2015 Aug 18. pii: gkv845. PMID:26286193<ref>PMID:26286193</ref> | |
| - | + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |
| - | + | </div> | |
| - | + | == References == | |
| - | [[Category: | + | <references/> |
| + | __TOC__ | ||
| + | </StructureSection> | ||
| + | [[Category: Ubiquitin--protein ligase]] | ||
| + | [[Category: Kumar, P]] | ||
[[Category: Wolberger, C]] | [[Category: Wolberger, C]] | ||
| - | [[Category: | + | [[Category: Bre1]] |
| + | [[Category: E2 conjugating enzyme]] | ||
| + | [[Category: Histone h2b]] | ||
| + | [[Category: Monoubiquitination of histone h2b at k123 in saccharomyces cerevisiae]] | ||
| + | [[Category: Nuclear protein]] | ||
| + | [[Category: Nucleus]] | ||
| + | [[Category: Pcna]] | ||
| + | [[Category: Rad18]] | ||
| + | [[Category: Ubc]] | ||
| + | [[Category: Ubiquitin]] | ||
| + | [[Category: Ubiquitination]] | ||
Revision as of 12:27, 2 September 2015
Structure of Rad6~Ub
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