6Q6T

Crystal structure (orthorombic form) of C36S mutant of thioredoxin h1 from Chlamydomonas reinhardtii

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 0.94 Å
  • R-Value Free: 0.166 
  • R-Value Work: 0.157 
  • R-Value Observed: 0.158 

wwPDB Validation   3D Report Full Report


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Literature

Structural and Biochemical Insights into the Reactivity of Thioredoxin h1 fromChlamydomonas reinhardtii.

Marchand, C.H., Fermani, S., Rossi, J., Gurrieri, L., Tedesco, D., Henri, J., Sparla, F., Trost, P., Lemaire, S.D., Zaffagnini, M.

(2019) Antioxidants (Basel) 8

  • DOI: 10.3390/antiox8010010
  • Primary Citation of Related Structures:  
    6Q46, 6Q47, 6Q6T, 6Q6U, 6Q6V

  • PubMed Abstract: 

    • 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 ...

    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 (p K a ) 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.

    Organizational Affiliation: 

    Laboratory of Molecular Plant Physiology, Department of Pharmacy and Biotechnology, University of Bologna, via Irnerio 42, 40126 Bologna, Italy. mirko.zaffagnini3@unibo.it.



Macromolecules
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(by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Thioredoxin H-typeA113Chlamydomonas reinhardtiiMutation(s): 1 
Gene Names: TRXH
UniProt
Find proteins for P80028 (Chlamydomonas reinhardtii)
Explore P80028 
Go to UniProtKB:  P80028
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP80028
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PEG
Query on PEG
Download Ideal Coordinates CCD File 
B [auth A],
C [auth A],
D [auth A],
E [auth A]		DI(HYDROXYETHYL)ETHER
C4 H10 O3
MTHSVFCYNBDYFN-UHFFFAOYSA-N		 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 0.94 Å
  • R-Value Free: 0.166 
  • R-Value Work: 0.157 
  • R-Value Observed: 0.158 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 60.777α = 90
b = 34.815β = 90
c = 48.158γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
Aimlessdata scaling
MOLREPphasing

Structure Validation

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Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
ItalyFARB2012-University of Bologna

Revision History  (Full details and data files)

  • Version 1.0: 2019-01-16
    Type: Initial release