4H6Q

Structure of oxidized Deinococcus radiodurans proline dehydrogenase complexed with L-tetrahydrofuroic acid


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.36 Å
  • R-Value Free: 0.181 
  • R-Value Work: 0.148 
  • R-Value Observed: 0.150 

Starting Model: experimental
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This is version 1.2 of the entry. See complete history


Literature

Crystal structures and kinetics of monofunctional proline dehydrogenase provide insight into substrate recognition and conformational changes associated with flavin reduction and product release.

Luo, M.Arentson, B.W.Srivastava, D.Becker, D.F.Tanner, J.J.

(2012) Biochemistry 51: 10099-10108

  • DOI: https://doi.org/10.1021/bi301312f
  • Primary Citation of Related Structures:  
    4H6Q, 4H6R

  • PubMed Abstract: 

    Proline dehydrogenase (PRODH) catalyzes the FAD-dependent oxidation of proline to Δ(1)-pyrroline-5-carboxylate, which is the first step of proline catabolism. Here, we report the structures of proline dehydrogenase from Deinococcus radiodurans in the oxidized state complexed with the proline analogue L-tetrahydrofuroic acid and in the reduced state with the proline site vacant. The analogue binds against the si face of the FAD isoalloxazine and is protected from bulk solvent by helix α8 and the β1-α1 loop. The FAD ribityl chain adopts two conformations in the E-S complex, which is unprecedented for flavoenzymes. One of the conformations is novel for the PRODH superfamily and may contribute to the low substrate affinity of Deinococcus PRODH. Reduction of the crystalline enzyme-inhibitor complex causes profound structural changes, including 20° butterfly bending of the isoalloxazine, crankshaft rotation of the ribityl, shifting of α8 by 1.7 Å, reconfiguration of the β1-α1 loop, and rupture of the Arg291-Glu64 ion pair. These changes dramatically open the active site to facilitate product release and allow electron acceptors access to the reduced flavin. The structures suggest that the ion pair, which is conserved in the PRODH superfamily, functions as the active site gate. Mutagenesis of Glu64 to Ala decreases the catalytic efficiency 27-fold, which demonstrates the importance of the gate. Mutation of Gly63 decreases the efficiency 140-fold, which suggests that flexibility of the β1-α1 loop is essential for optimal catalysis. The large conformational changes that are required to form the E-S complex suggest that conformational selection plays a role in substrate recognition.


  • Organizational Affiliation

    Department of Chemistry, University of Missouri-Columbia, Columbia, MO 65211, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Proline dehydrogenaseA,
B [auth C]
312Deinococcus radiodurans R1 = ATCC 13939 = DSM 20539Mutation(s): 0 
Gene Names: DR_0814PROLINE DEHYDROGENASE
EC: 1.5.99.8
UniProt
Find proteins for Q9RW55 (Deinococcus radiodurans (strain ATCC 13939 / DSM 20539 / JCM 16871 / CCUG 27074 / LMG 4051 / NBRC 15346 / NCIMB 9279 / VKM B-1422 / R1))
Explore Q9RW55 
Go to UniProtKB:  Q9RW55
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9RW55
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.36 Å
  • R-Value Free: 0.181 
  • R-Value Work: 0.148 
  • R-Value Observed: 0.150 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 44.469α = 90
b = 95.462β = 90
c = 136.393γ = 90
Software Package:
Software NamePurpose
SCALAdata scaling
PHENIXrefinement
PDB_EXTRACTdata extraction
XDSdata reduction
MOLREPphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2012-11-28
    Type: Initial release
  • Version 1.1: 2013-01-02
    Changes: Database references
  • Version 1.2: 2023-09-20
    Changes: Data collection, Database references, Derived calculations, Refinement description