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Structural snapshots along the reaction mechanism of the atypical poplar thioredoxin‐like2.1
Author(s) -
Chibani Kamel,
Saul Frederick,
Didierjean Claude,
Rouhier Nicolas,
Haouz Ahmed
Publication year - 2018
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1002/1873-3468.13009
Subject(s) - thioredoxin , dimer , chemistry , glutathione , active site , biochemistry , folding (dsp implementation) , biophysics , catalysis , stereochemistry , enzyme , biology , organic chemistry , electrical engineering , engineering
Plastidial thioredoxin ( TRX )‐like2.1 proteins are atypical thioredoxins possessing a WCRKC active site signature and using glutathione for recycling. To obtain structural information supporting the peculiar catalytic mechanisms and target proteins of these TRX s, we solved the crystal structures of poplar TRX ‐like2.1 in oxidized and reduced states and of mutated variants. These structures share similar folding with TRX s exhibiting the canonical WCGPC signature. Moreover, the overall conformation is not altered by reduction of the catalytic disulfide bond or in a C45S/C67S variant that formed a disulfide‐bridged dimer possibly mimicking reaction intermediates with target proteins. Modeling of the interaction of TRX ‐like2.1 with both NADPH ‐ and ferredoxin‐thioredoxin reductases (FTR) indicates that the presence of Arg43 and Lys44 residues likely precludes reduction by the plastidial FTR.