View source for 5xbo


==Lanthanoid tagging via an unnatural amino acid for protein structure characterization==
<StructureSection load='5xbo' size='340' side='right'caption='[[5xbo]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5xbo]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5XBO OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5XBO FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=TB:TERBIUM(III)+ION'>TB</scene></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=5xbo FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5xbo OCA], [https://pdbe.org/5xbo PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5xbo RCSB], [https://www.ebi.ac.uk/pdbsum/5xbo PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5xbo ProSAT]</span></td></tr>
</table>
== Function ==
[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;">
== Publication Abstract from PubMed ==
Lanthanoid pseudo-contact shift (PCS) provides long-range structural information between a paramagnetic tag and protein nuclei. However, for proteins with native cysteines, site-specific attachment may only utilize functional groups orthogonal to sulfhydryl chemistry. Here we report two lanthanoid probes, DTTA-C3-yne and DTTA-C4-yne, which can be conjugated to an unnatural amino acid pAzF in the target protein via azide-alkyne cycloaddition. Demonstrated with ubiquitin and cysteine-containing enzyme EIIB, we show that large PCSs of distinct profiles can be generated for each tag/lanthanoid combination. The DTTA-based lanthanoid tags are associated with large magnetic susceptibility tensors owing to the rigidity of the tags. In particular, introduction of the DTTA-C3 tag affords intermolecular PCSs and enables structural characterization of a transient protein complex between ubiquitin and a UBA domain. Together, we have expanded the repertoire of paramagnetic tags and the applicability of paramagnetic NMR.

Lanthanoid tagging via an unnatural amino acid for protein structure characterization.,Jiang WX, Gu XH, Dong X, Tang C J Biomol NMR. 2017 Apr;67(4):273-282. doi: 10.1007/s10858-017-0106-9. Epub 2017, Apr 1. PMID:28365903<ref>PMID:28365903</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5xbo" style="background-color:#fffaf0;"></div>

==See Also==
*[[UV excision repair protein|UV excision repair protein]]
== References ==
<references/>
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</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Dong X]]
[[Category: Gu X]]
[[Category: Jiang W]]
[[Category: Tang C]]