1DY7

Cytochrome cd1 Nitrite Reductase, CO complex


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.6 Å
  • R-Value Free: 0.199 
  • R-Value Work: 0.178 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Proton-Coupled Structural Changes Upon Binding of Carbon Monoxide to Cytochrome Cd(1): A Combined Flash Photolysis and X-Ray Crystallography Study

Sjogren, T.Svensson-Ek, M.Hajdu, J.Brzezinski, P.

(2000) Biochemistry 39: 10967


  • PubMed Abstract: 
  • We have investigated dynamic events after flash photolysis of CO from reduced cytochrome cd(1) nitrite reductase (NiR) from Paracoccus pantotrophus (formerly Thiosphaera pantotropha). Upon pulsed illumination of the cytochrome cd(1)-CO complex, at 46 ...

    We have investigated dynamic events after flash photolysis of CO from reduced cytochrome cd(1) nitrite reductase (NiR) from Paracoccus pantotrophus (formerly Thiosphaera pantotropha). Upon pulsed illumination of the cytochrome cd(1)-CO complex, at 460 nm, a rapid (<50 ns) absorbance change, attributed to dissociation of CO, was observed. This was followed by a biphasic rearrangement with rate constants of 1.7 x 10(4) and 2.5 x 10(3) s(-1) at pH 8.0. Both parts of the biphasic rearrangement phases displayed the same kinetic difference spectrum in the region of 400-660 nm. The slower of the two processes was accompanied by proton uptake from solution (0.5 proton per active site at pH 7.5-8.5). After photodissociation, the CO ligand recombined at a rate of 12 s(-1) (at 1 mM CO and pH 8.0), accompanied by proton release. The crystal structure of reduced cytochrome cd(1) in complex with CO was determined to a resolution of 1.57 A. The structure shows that CO binds to the iron of the d(1) heme in the active site. The ligation of the c heme is unchanged in the complex. A comparison of the structures of the reduced, unligated NiR and the NiR-CO complex indicates changes in the puckering of the d(1) heme as well as rearrangements in the hydrogen-bonding network and solvent organization in the substrate binding pocket at the d(1) heme. Since the CO ligand binds to heme d(1) and there are structural changes in the d(1) pocket upon CO binding, it is likely that the proton uptake or release observed after flash-induced CO dissociation is due to changes of the protonation state of groups in the active site. Such proton-coupled structural changes associated with ligand binding are likely to affect the redox potential of heme d(1) and may regulate the internal electron transfer from heme c to heme d(1).


    Related Citations: 
    • Haem-Ligand Switching During Catalysis in Crystals of a Nitrogen-Cycle Enzyme
      Williams, P.A.,Fulop, V.,Garman, E.F.,Saunders, N.F.,Ferguson, S.J.,Hajdu, J.
      (1997) Nature 389: 406


    Organizational Affiliation

    Department of Biochemistry, Uppsala University, Biomedical Center, Box 576, SE-751 23 Uppsala, Sweden.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
NITRITE REDUCTASE
A, B
567Paracoccus pantotrophusGene Names: nirS
EC: 1.7.99.1, 1.7.2.1
Find proteins for P72181 (Paracoccus pantotrophus)
Go to UniProtKB:  P72181
Small Molecules
Ligands 5 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

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Download CCD File 
A, B
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
GOL
Query on GOL

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A, B
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
HEC
Query on HEC

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Download CCD File 
B
HEME C
C34 H34 Fe N4 O4
HXQIYSLZKNYNMH-LJNAALQVSA-N
 Ligand Interaction
CMO
Query on CMO

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Download CCD File 
A, B
CARBON MONOXIDE
C O
UGFAIRIUMAVXCW-UHFFFAOYSA-N
 Ligand Interaction
DHE
Query on DHE

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Download CCD File 
A, B
HEME D
C34 H32 Fe N4 O10
XLQCGNUTSJTZNF-SOFPVUHFDM
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.6 Å
  • R-Value Free: 0.199 
  • R-Value Work: 0.178 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 106.940α = 90.00
b = 61.040β = 111.77
c = 100.390γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
SCALEPACKdata scaling
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2000-09-24
    Type: Initial release
  • Version 1.1: 2011-07-07
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance