View source for 6q47


==Crystal structure of partially oxidized thioredoxin h1 from Chlamydomonas reinhardtii==
<StructureSection load='6q47' size='340' side='right'caption='[[6q47]], [[Resolution|resolution]] 1.57&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6q47]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Chlamydomonas_reinhardtii Chlamydomonas reinhardtii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6Q47 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6Q47 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]] 1.57&#8491;</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=6q47 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6q47 OCA], [https://pdbe.org/6q47 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6q47 RCSB], [https://www.ebi.ac.uk/pdbsum/6q47 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6q47 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/TRXH_CHLRE TRXH_CHLRE] Participates in various redox reactions through the reversible oxidation of the active center dithiol to a disulfide. The H form is known to activate a number of cytosolic enzymes.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Thioredoxins (TRXs) are major protein disulfide reductases of the cell. Their redox activity relies on a conserved Trp-Cys-(Gly/Pro)-Pro-Cys active site bearing two cysteine (Cys) residues that can be found either as free thiols (reduced TRXs) or linked together by a disulfide bond (oxidized TRXs) during the catalytic cycle. Their reactivity is crucial for TRX activity, and depends on the active site microenvironment. Here, we solved and compared the 3D structure of reduced and oxidized TRX h1 from Chlamydomonas reinhardtii (CrTRXh1). The three-dimensional structure was also determined for mutants of each active site Cys. Structural alignments of CrTRXh1 with other structurally solved plant TRXs showed a common spatial fold, despite the low sequence identity. Structural analyses of CrTRXh1 revealed that the protein adopts an identical conformation independently from its redox state. Treatment with iodoacetamide (IAM), a Cys alkylating agent, resulted in a rapid and pH-dependent inactivation of CrTRXh1. Starting from fully reduced CrTRXh1, we determined the acid dissociation constant (pKa) of each active site Cys by Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry analyses coupled to differential IAM-based alkylation. Based on the diversity of catalytic Cys deprotonation states, the mechanisms and structural features underlying disulfide redox activity are discussed.

Structural and Biochemical Insights into the Reactivity of Thioredoxin h1 from Chlamydomonas reinhardtii.,Marchand CH, Fermani S, Rossi J, Gurrieri L, Tedesco D, Henri J, Sparla F, Trost P, Lemaire SD, Zaffagnini M Antioxidants (Basel). 2019 Jan 1;8(1). pii: antiox8010010. doi:, 10.3390/antiox8010010. PMID:30609656<ref>PMID:30609656</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6q47" style="background-color:#fffaf0;"></div>

==See Also==
*[[Thioredoxin 3D structures|Thioredoxin 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Chlamydomonas reinhardtii]]
[[Category: Large Structures]]
[[Category: Fermani S]]
[[Category: Lemaire SD]]
[[Category: Zaffagnini M]]