View source for 2yb6


==Native human Rad6==
<StructureSection load='2yb6' size='340' side='right'caption='[[2yb6]], [[Resolution|resolution]] 1.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2yb6]] is a 1 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=2YB6 OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=2YB6 FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BME:BETA-MERCAPTOETHANOL'>BME</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[2ybf|2ybf]], [[2y4w|2y4w]], [[1nxa|1nxa]], [[1jas|1jas]]</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=2yb6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2yb6 OCA], [http://pdbe.org/2yb6 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2yb6 RCSB], [http://www.ebi.ac.uk/pdbsum/2yb6 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=2yb6 ProSAT]</span></td></tr>
</table>
== Function ==
[[http://www.uniprot.org/uniprot/UBE2B_HUMAN UBE2B_HUMAN]] Accepts ubiquitin from the E1 complex and catalyzes its covalent attachment to other proteins. In association with the E3 enzyme BRE1 (RNF20 and/or RNF40), it plays a role in transcription regulation by catalyzing the monoubiquitination of histone H2B at 'Lys-120' to form H2BK120ub1. H2BK120ub1 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 vitro catalyzes 'Lys-11'-, as well as 'Lys-48'- and 'Lys-63'-linked polyubiquitination. Required for postreplication repair of UV-damaged DNA. Associates to the E3 ligase RAD18 to form the UBE2B-RAD18 ubiquitin ligase complex involved in mono-ubiquitination of DNA-associated PCNA on 'Lys-164'. May be involved in neurite outgrowth.<ref>PMID:1717990</ref> <ref>PMID:16337599</ref> <ref>PMID:17130289</ref> <ref>PMID:17108083</ref> <ref>PMID:20061386</ref>  
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== Publication Abstract from PubMed ==
In ubiquitin conjugation, different combinations of E2 and E3 enzymes catalyse either monoubiquitination or ubiquitin chain formation. The E2/E3 complex Rad6/Rad18 exclusively monoubiquitinates the proliferating cell nuclear antigen (PCNA) to signal for "error prone" DNA damage tolerance, whereas a different set of conjugation enzymes is required for ubiquitin chain formation on PCNA. Here we show that human E2 enzyme Rad6b is intrinsically capable of catalyzing ubiquitin chain formation. This activity is prevented during PCNA ubiquitination by the interaction of Rad6 with E3 enzyme Rad18. Using NMR and X-ray crystallography we show that the R6BD of Rad18 inhibits this activity by competing with ubiquitin for a noncovalent "backside" binding site on Rad6. Our findings provide mechanistic insights into how E3 enzymes can regulate the ubiquitin conjugation process.

E3 ligase Rad18 promotes monoubiquitination rather than ubiquitin chain formation by E2 enzyme Rad6.,Hibbert RG, Huang A, Boelens R, Sixma TK Proc Natl Acad Sci U S A. 2011 Apr 5;108(14):5590-5. Epub 2011 Mar 21. PMID:21422291<ref>PMID:21422291</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 2yb6" style="background-color:#fffaf0;"></div>

==See Also==
*[[Ubiquitin conjugating enzyme|Ubiquitin conjugating enzyme]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Human]]
[[Category: Large Structures]]
[[Category: Hibbert, R G]]
[[Category: Sixma, T K]]
[[Category: Ligase]]
[[Category: Translesion synthesis]]
[[Category: Ubiquitin chain synthesis]]