View source for 2voc


==THIOREDOXIN A ACTIVE SITE MUTANTS FORM MIXED DISULFIDE DIMERS THAT RESEMBLE ENZYME-SUBSTRATE REACTION INTERMEDIATE==
<StructureSection load='2voc' size='340' side='right'caption='[[2voc]], [[Resolution|resolution]] 1.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2voc]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Bacillus_subtilis_subsp._subtilis_str._168 Bacillus subtilis subsp. subtilis str. 168]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2VOC OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2VOC 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]] 1.5&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=PEG:DI(HYDROXYETHYL)ETHER'>PEG</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=2voc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2voc OCA], [https://pdbe.org/2voc PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2voc RCSB], [https://www.ebi.ac.uk/pdbsum/2voc PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2voc ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/THIO_BACSU THIO_BACSU] Participates in various redox reactions through the reversible oxidation of its active center dithiol to a disulfide and catalyzes dithiol-disulfide exchange reactions.
== 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/vo/2voc_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=2voc ConSurf].
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== Publication Abstract from PubMed ==
Thioredoxin functions in nearly all organisms as the major thiol-disulfide oxidoreductase within the cytosol. Its prime purpose is to maintain cysteine-containing proteins in the reduced state by converting intramolecular disulfide bonds into dithiols in a disulfide exchange reaction. Thioredoxin has been reported to contribute to a wide variety of physiological functions by interacting with specific sets of substrates in different cell types. To investigate the function of the essential thioredoxin A (TrxA) in the low-GC Gram-positive bacterium Bacillus subtilis, we purified wild-type TrxA and three mutant TrxA proteins that lack either one or both of the two cysteine residues in the CxxC active site. The pure proteins were used for substrate-binding studies known as "mixed disulfide fishing" in which covalent disulfide-bonded reaction intermediates can be visualized. An unprecedented finding is that both active-site cysteine residues can form mixed disulfides with substrate proteins when the other active-site cysteine is absent, but only the N-terminal active-site cysteine forms stable interactions. A second novelty is that both single-cysteine mutant TrxA proteins form stable homodimers due to thiol oxidation of the remaining active-site cysteine residue. To investigate whether these dimers resemble mixed enzyme-substrate disulfides, the structure of the most abundant dimer, C32S, was characterized by X-ray crystallography. This yielded a high-resolution (1.5A) X-ray crystallographic structure of a thioredoxin homodimer from a low-GC Gram-positive bacterium. The C32S TrxA dimer can be regarded as a mixed disulfide reaction intermediate of thioredoxin, which reveals the diversity of thioredoxin/substrate-binding modes.

Thioredoxin A active-site mutants form mixed disulfide dimers that resemble enzyme-substrate reaction intermediates.,Kouwen TR, Andrell J, Schrijver R, Dubois JY, Maher MJ, Iwata S, Carpenter EP, van Dijl JM J Mol Biol. 2008 Jun 6;379(3):520-34. Epub 2008 Apr 10. PMID:18455736<ref>PMID:18455736</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 2voc" style="background-color:#fffaf0;"></div>

==See Also==
*[[Thioredoxin 3D structures|Thioredoxin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Bacillus subtilis subsp. subtilis str. 168]]
[[Category: Large Structures]]
[[Category: Andrell J]]
[[Category: Carpenter EP]]
[[Category: Dubois JYF]]
[[Category: Iwata S]]
[[Category: Kouwen TRHM]]
[[Category: Maher MJ]]
[[Category: Schrijver R]]
[[Category: Van Dijl JM]]