1NM5

R. rubrum transhydrogenase (dI.Q132N)2(dIII)1 asymmetric complex


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.236 
  • R-Value Observed: 0.238 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

Glutamine 132 in the NAD(H)-binding component of proton-translocating transhydrogenase tethers the nucleotides before hydride transfer.

van Boxel, G.I.Quirk, P.G.Cotton, N.P.White, S.A.Jackson, J.B.

(2003) Biochemistry 42: 1217-1226

  • DOI: https://doi.org/10.1021/bi027032e
  • Primary Citation of Related Structures:  
    1NM5

  • PubMed Abstract: 

    Transhydrogenase, found in bacterial membranes and inner mitochondrial membranes of animal cells, couples the redox reaction between NAD(H) and NADP(H) to proton translocation. In this work, the invariant Gln132 in the NAD(H)-binding component (dI) of the Rhodospirillum rubrum transhydrogenase was substituted with Asn (to give dI.Q132N). Mixtures of the mutant protein and the NADP(H)-binding component (dIII) of the enzyme readily produced an asymmetric complex, (dI.Q132N)(2)dIII(1). The X-ray structure of the complex revealed specific changes in the interaction between bound nicotinamide nucleotides and the protein at the hydride transfer site. The first-order rate constant of the redox reaction between nucleotides bound to (dI.Q132N)(2)dIII(1) was <1% of that for the wild-type complex, and the deuterium isotope effect was significantly decreased. The nucleotide binding properties of the dI component in the complex were asymmetrically affected by the Gln-to-Asn mutation. In intact, membrane-bound transhydrogenase, the substitution completely abolished all catalytic activity. The results suggest that Gln132 in the wild-type enzyme behaves as a "tether" or a "tie" in the mutual positioning of the (dihydro)nicotinamide rings of NAD(H) and NADP(H) for hydride transfer during the conformational changes that are coupled to the translocation of protons across the membrane. This ensures that hydride transfer is properly gated and does not take place in the absence of proton translocation.


  • Organizational Affiliation

    School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.


Macromolecules
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Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
NAD(P) transhydrogenase subunit alpha part 1
A, B
384Rhodospirillum rubrumMutation(s): 1 
Gene Names: PNT
EC: 1.6.1.2 (PDB Primary Data), 7.1.1.1 (UniProt)
UniProt
Find proteins for Q2RSB2 (Rhodospirillum rubrum (strain ATCC 11170 / ATH 1.1.1 / DSM 467 / LMG 4362 / NCIMB 8255 / S1))
Explore Q2RSB2 
Go to UniProtKB:  Q2RSB2
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ2RSB2
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
NAD(P) transhydrogenase subunit beta203Rhodospirillum rubrumMutation(s): 0 
Gene Names: PNT
EC: 1.6.1.2 (PDB Primary Data), 7.1.1.1 (UniProt)
UniProt
Find proteins for Q2RSB4 (Rhodospirillum rubrum (strain ATCC 11170 / ATH 1.1.1 / DSM 467 / LMG 4362 / NCIMB 8255 / S1))
Explore Q2RSB4 
Go to UniProtKB:  Q2RSB4
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ2RSB4
Sequence Annotations
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  • Reference Sequence
Small Molecules
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.236 
  • R-Value Observed: 0.238 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 71.939α = 90
b = 73.886β = 90
c = 205.257γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
MOSFLMdata reduction
CCP4data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2004-01-13
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Non-polymer description, Version format compliance
  • Version 1.3: 2021-10-27
    Changes: Database references, Derived calculations
  • Version 1.4: 2023-08-16
    Changes: Data collection, Refinement description