4DSS

Crystal structure of peroxiredoxin Ahp1 from Saccharomyces cerevisiae in complex with thioredoxin Trx2


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.259 
  • R-Value Work: 0.219 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structural Snapshots of Yeast Alkyl Hydroperoxide Reductase Ahp1 Peroxiredoxin Reveal a Novel Two-cysteine Mechanism of Electron Transfer to Eliminate Reactive Oxygen Species.

Lian, F.M.Yu, J.Ma, X.X.Yu, X.J.Chen, Y.Zhou, C.Z.

(2012) J.Biol.Chem. 287: 17077-17087

  • DOI: 10.1074/jbc.M112.357368
  • Primary Citation of Related Structures:  4DSQ, 4DSR

  • PubMed Abstract: 
  • Peroxiredoxins (Prxs) are thiol-specific antioxidant proteins that protect cells against reactive oxygen species and are involved in cellular signaling pathways. Alkyl hydroperoxide reductase Ahp1 belongs to the Prx5 subfamily and is a two-cysteine ( ...

    Peroxiredoxins (Prxs) are thiol-specific antioxidant proteins that protect cells against reactive oxygen species and are involved in cellular signaling pathways. Alkyl hydroperoxide reductase Ahp1 belongs to the Prx5 subfamily and is a two-cysteine (2-Cys) Prx that forms an intermolecular disulfide bond. Enzymatic assays and bioinformatics enabled us to re-assign the peroxidatic cysteine (C(P)) to Cys-62 and the resolving cysteine (C(R)) to Cys-31 but not the previously reported Cys-120. Thus Ahp1 represents the first 2-Cys Prx with a peroxidatic cysteine after the resolving cysteine in the primary sequence. We also found the positive cooperativity of the substrate t-butyl hydroperoxide binding to Ahp1 homodimer at a Hill coefficient of ∼2, which enabled Ahp1 to eliminate hydroperoxide at much higher efficiency. To gain the structural insights into the catalytic cycle of Ahp1, we determined the crystal structures of Ahp1 in the oxidized, reduced, and Trx2-complexed forms at 2.40, 2.91, and 2.10 Å resolution, respectively. Structural superposition of the oxidized to the reduced form revealed significant conformational changes at the segments containing C(P) and C(R). An intermolecular C(P)-C(R) disulfide bond crossing the A-type dimer interface distinguishes Ahp1 from other typical 2-Cys Prxs. The structure of the Ahp1-Trx2 complex showed for the first time how the electron transfers from thioredoxin to a peroxidase with a thioredoxin-like fold. In addition, site-directed mutagenesis in combination with enzymatic assays suggested that the peroxidase activity of Ahp1 would be altered upon the urmylation (covalently conjugated to ubiquitin-related modifier Urm1) of Lys-32.


    Organizational Affiliation

    Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, China.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Peroxiredoxin type-2
A
176Saccharomyces cerevisiae (strain ATCC 204508 / S288c)Gene Names: AHP1
EC: 1.11.1.15
Find proteins for P38013 (Saccharomyces cerevisiae (strain ATCC 204508 / S288c))
Go to UniProtKB:  P38013
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Thioredoxin-2
B
112Saccharomyces cerevisiae (strain ATCC 204508 / S288c)Gene Names: TRX2 (TRX1)
Find proteins for P22803 (Saccharomyces cerevisiae (strain ATCC 204508 / S288c))
Go to UniProtKB:  P22803
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.259 
  • R-Value Work: 0.219 
  • Space Group: C 2 2 21
Unit Cell:
Length (Å)Angle (°)
a = 55.703α = 90.00
b = 133.415β = 90.00
c = 78.238γ = 90.00
Software Package:
Software NamePurpose
ADSCdata collection
MOLREPphasing
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-04-11
    Type: Initial release
  • Version 1.1: 2012-06-13
    Type: Database references