1tbe: Difference between revisions
New page: left|200px<br /> <applet load="1tbe" size="450" color="white" frame="true" align="right" spinBox="true" caption="1tbe, resolution 2.4Å" /> '''STRUCTURE OF TETRAUB... |
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== | ==STRUCTURE OF TETRAUBIQUITIN SHOWS HOW MULTIUBIQUITIN CHAINS CAN BE FORMED== | ||
Eukaryotic proteins are targeted for degradation by covalent ligation of | <StructureSection load='1tbe' size='340' side='right'caption='[[1tbe]], [[Resolution|resolution]] 2.40Å' scene=''> | ||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1tbe]] 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=1TBE OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1TBE FirstGlance]. <br> | |||
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.4Å</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=1tbe FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1tbe OCA], [https://pdbe.org/1tbe PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1tbe RCSB], [https://www.ebi.ac.uk/pdbsum/1tbe PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1tbe ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/UBC_HUMAN UBC_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> | |||
== Evolutionary Conservation == | |||
[[Image:Consurf_key_small.gif|200px|right]] | |||
Check<jmol> | |||
<jmolCheckbox> | |||
<scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/tb/1tbe_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked> | |||
<text>to colour the structure by Evolutionary Conservation</text> | |||
</jmolCheckbox> | |||
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1tbe ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Eukaryotic proteins are targeted for degradation by covalent ligation of multiubiquitin chains. In these multiubiquitin chains, successive ubiquitins are linked by an isopeptide bond involving the side chain of Lys48 and the carboxyl group of the C-terminus (Gly76). The crystal structure of a tetraubiquitin chain (Ub4) has been determined and refined at 2.4 A resolution. The molecule exhibits both translational and 2-fold rotational symmetry; each pair of (rotationally symmetric) ubiquitin molecules in Ub4 is related to the next pair by a simple translation. The 2-fold symmetry in each pair of ubiquitin molecules is quite different from the 2-fold symmetry observed in the previously determined structure of isolated diubiquitin. There are multiple hydrophilic contacts among the four ubiquitin molecules, but the hydrophobic surface formed in the middle of diubiquitin is not seen. The structure of the tetraubiquitin chain demonstrates how a multiubiquitin chain of any length can be formed. | |||
Structure of tetraubiquitin shows how multiubiquitin chains can be formed.,Cook WJ, Jeffrey LC, Kasperek E, Pickart CM J Mol Biol. 1994 Feb 18;236(2):601-9. PMID:8107144<ref>PMID:8107144</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 1tbe" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[3D structures of ubiquitin|3D structures of ubiquitin]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
[[Category: | [[Category: Large Structures]] | ||
[[Category: Cook | [[Category: Cook WJ]] | ||
[[Category: Jeffrey | [[Category: Jeffrey LC]] | ||
[[Category: Kasperek | [[Category: Kasperek E]] | ||
[[Category: Pickart | [[Category: Pickart CM]] | ||
