1KQC

Structure of Nitroreductase from E. cloacae Complex with Inhibitor Acetate


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.219 
  • R-Value Work: 0.187 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Structures of nitroreductase in three states: effects of inhibitor binding and reduction.

Haynes, C.A.Koder, R.L.Miller, A.F.Rodgers, D.W.

(2002) J.Biol.Chem. 277: 11513-11520

  • DOI: 10.1074/jbc.M111334200
  • Primary Citation of Related Structures:  1KQB, 1KQD

  • PubMed Abstract: 
  • The crystal structure of the nitroreductase enzyme from Enterobacter cloacae has been determined for the oxidized form in separate complexes with benzoate and acetate inhibitors and for the two-electron reduced form. Nitroreductase is a member of a g ...

    The crystal structure of the nitroreductase enzyme from Enterobacter cloacae has been determined for the oxidized form in separate complexes with benzoate and acetate inhibitors and for the two-electron reduced form. Nitroreductase is a member of a group of enzymes that reduce a broad range of nitroaromatic compounds and has potential uses in chemotherapy and bioremediation. The monomers of the nitroreductase dimer adopt an alpha+beta fold and together bind two flavin mononucleotide prosthetic groups at the dimer interface. In the oxidized enzyme, the flavin ring system adopts a strongly bent (16 degrees ) conformation, and the bend increases (25 degrees ) in the reduced form of the enzyme, roughly the conformation predicted for reduced flavin free in solution. Because free oxidized flavin is planar, the induced bend in the oxidized enzyme may favor reduction, and it may also account for the characteristic inability of the enzyme to stabilize the one electron-reduced semiquinone flavin, which is also planar. Both inhibitors bind over the pyrimidine and central rings of the flavin in partially overlapping sites. Comparison of the two inhibitor complexes shows that a portion of helix H6 can flex to accommodate the differently sized inhibitors suggesting a mechanism for accommodating varied substrates.


    Organizational Affiliation

    Department of Molecular and Cellular Biochemistry, The University of Kentucky, Lexington, Kentucky 40536, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
OXYGEN-INSENSITIVE NAD(P)H NITROREDUCTASE
A, B, C, D
217Enterobacter cloacaeGene Names: nfsB (nfnB, nfsI)
EC: 1.-.-.-
Find proteins for Q01234 (Enterobacter cloacae)
Go to UniProtKB:  Q01234
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
FMN
Query on FMN

Download SDF File 
Download CCD File 
A, B, C, D
FLAVIN MONONUCLEOTIDE
RIBOFLAVIN MONOPHOSPHATE
C17 H21 N4 O9 P
FVTCRASFADXXNN-SCRDCRAPSA-N
 Ligand Interaction
ACT
Query on ACT

Download SDF File 
Download CCD File 
A, B, C, D
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.219 
  • R-Value Work: 0.187 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 52.785α = 90.00
b = 79.606β = 93.63
c = 97.138γ = 90.00
Software Package:
Software NamePurpose
CNSrefinement
CNSphasing
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2002-02-13
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-10-11
    Type: Refinement description