3IKV

Crystal structure of a Rex-family repressor R90D mutant from Thermus aquaticus


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.256 
  • R-Value Work: 0.218 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structural basis for NADH/NAD+ redox sensing by a Rex family repressor.

McLaughlin, K.J.Strain-Damerell, C.M.Xie, K.Brekasis, D.Soares, A.S.Paget, M.S.Kielkopf, C.L.

(2010) Mol.Cell 38: 563-575

  • DOI: 10.1016/j.molcel.2010.05.006
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Nicotinamide adenine dinucleotides have emerged as key signals of the cellular redox state. Yet the structural basis for allosteric gene regulation by the ratio of reduced NADH to oxidized NAD(+) is poorly understood. A key sensor among Gram-positive ...

    Nicotinamide adenine dinucleotides have emerged as key signals of the cellular redox state. Yet the structural basis for allosteric gene regulation by the ratio of reduced NADH to oxidized NAD(+) is poorly understood. A key sensor among Gram-positive bacteria, Rex represses alternative respiratory gene expression until a limited oxygen supply elevates the intracellular NADH:NAD(+) ratio. Here we investigate the molecular mechanism for NADH/NAD(+) sensing among Rex family members by determining structures of Thermus aquaticus Rex bound to (1) NAD(+), (2) DNA operator, and (3) without ligand. Comparison with the Rex/NADH complex reveals that NADH releases Rex from the DNA site following a 40 degrees closure between the dimeric subunits. Complementary site-directed mutagenesis experiments implicate highly conserved residues in NAD-responsive DNA-binding activity. These rare views of a redox sensor in action establish a means for slight differences in the nicotinamide charge, pucker, and orientation to signal the redox state of the cell.


    Organizational Affiliation

    Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Redox-sensing transcriptional repressor rex
A, B
207Thermus thermophilus (strain HB27 / ATCC BAA-163 / DSM 7039)Mutation(s): 1 
Gene Names: rex
Find proteins for Q72I39 (Thermus thermophilus (strain HB27 / ATCC BAA-163 / DSM 7039))
Go to UniProtKB:  Q72I39
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

Download SDF File 
Download CCD File 
A
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.256 
  • R-Value Work: 0.218 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 56.995α = 90.00
b = 88.222β = 90.00
c = 99.576γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data collection
PHASERphasing
HKL-2000data scaling
CNSrefinement
HKL-2000data reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-06-09
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance