2FMY

CO-dependent transcription factor CooA from Carboxydothermus hydrogenoformans (Imidazole-bound form)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free: 0.247 
  • R-Value Work: 0.207 
  • R-Value Observed: 0.209 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Crystal Structure of CO-sensing Transcription Activator CooA Bound to Exogenous Ligand Imidazole

Komori, H.Inagaki, S.Yoshioka, S.Aono, S.Higuchi, Y.

(2007) J Mol Biol 367: 864-871

  • DOI: 10.1016/j.jmb.2007.01.043
  • Primary Citation of Related Structures:  
    2FMY

  • PubMed Abstract: 
  • CooA is a CO-dependent transcriptional activator and transmits a CO-sensing signal to a DNA promoter that controls the expression of the genes responsible for CO metabolism. CooA contains a b-type heme as the active site for sensing CO. CO binding to ...

    CooA is a CO-dependent transcriptional activator and transmits a CO-sensing signal to a DNA promoter that controls the expression of the genes responsible for CO metabolism. CooA contains a b-type heme as the active site for sensing CO. CO binding to the heme induces a conformational change that switches CooA from an inactive to an active DNA-binding form. Here, we report the crystal structure of an imidazole-bound form of CooA from Carboxydothermus hydrogenoformans (Ch-CooA). In the resting form, Ch-CooA has a six-coordinate ferrous heme with two endogenous axial ligands, the alpha-amino group of the N-terminal amino acid and a histidine residue. The N-terminal amino group of CooA that is coordinated to the heme iron is replaced by CO. This substitution presumably triggers a structural change leading to the active form. The crystal structure of Ch-CooA reveals that imidazole binds to the heme, which replaces the N terminus, as does CO. The dissociated N terminus is positioned approximately 16 A from the heme iron in the imidazole-bound form. In addition, the heme plane is rotated by 30 degrees about the normal of the porphyrin ring compared to that found in the inactive form of Rhodospirillum rubrum CooA. Even though the ligand exchange, imidazole-bound Ch-CooA remains in the inactive form for DNA binding. These results indicate that the release of the N terminus resulting from imidazole binding is not sufficient to activate CooA. The structure provides new insights into the structural changes required to achieve activation.


    Organizational Affiliation

    Department of Life Science, Graduate School of Life Science, University of Hyogo and Himeji Institute of Technology, 3-2-1 Koto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
carbon monoxide oxidation system transcription regulator CooA-1ABCD220Carboxydothermus hydrogenoformansMutation(s): 0 
Find proteins for Q3AB29 (Carboxydothermus hydrogenoformans (strain ATCC BAA-161 / DSM 6008 / Z-2901))
Explore Q3AB29 
Go to UniProtKB:  Q3AB29
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
HEM
Query on HEM

Download CCD File 
A, B, C, D
PROTOPORPHYRIN IX CONTAINING FE
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
IMD
Query on IMD

Download CCD File 
A, B, C, D
IMIDAZOLE
C3 H5 N2
RAXXELZNTBOGNW-UHFFFAOYSA-O
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free: 0.247 
  • R-Value Work: 0.207 
  • R-Value Observed: 0.209 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 61.654α = 90
b = 93.93β = 104.73
c = 91.901γ = 90
Software Package:
Software NamePurpose
CNSrefinement
HKL-2000data reduction
CCP4data scaling
SHARPphasing
REFMACrefinement

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-01-16
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Advisory, Version format compliance