1KRJ

Engineering Calcium-binding site into Cytochrome c Peroxidase (CcP)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Work: 0.192 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Conversion of an engineered potassium-binding site into a calcium-selective site in cytochrome c peroxidase.

Bonagura, C.A.Bhaskar, B.Sundaramoorthy, M.Poulos, T.L.

(1999) J.Biol.Chem. 274: 37827-37833


  • PubMed Abstract: 
  • We have previously shown that the K(+) site found in ascorbate peroxidase can be successfully engineered into the closely homologous peroxidase, cytochrome c peroxidase (CCP) (Bonagura, C. A. , Sundaramoorthy, M., Pappa, H. S., Patterson, W. R., and ...

    We have previously shown that the K(+) site found in ascorbate peroxidase can be successfully engineered into the closely homologous peroxidase, cytochrome c peroxidase (CCP) (Bonagura, C. A. , Sundaramoorthy, M., Pappa, H. S., Patterson, W. R., and Poulos, T. L. (1996) Biochemistry 35, 6107-6115; Bonagura, C. A., Sundaramoorthy, M., Bhaskar, B., and Poulos, T. L. (1999) Biochemistry 38, 5538-5545). All other peroxidases bind Ca(2+) rather than K(+). Using the K(+)-binding CCP mutant (CCPK2) as a template protein, together with observations from structural modeling, mutants were designed that should bind Ca(2+) selectively. The crystal structure of the first generation mutant, CCPCA1, showed that a smaller cation, perhaps Na(+), is bound instead of Ca(2+). This is probably because the full eight-ligand coordination sphere did not form owing to a local disordering of one of the essential cation ligands. Based on these observations, a second mutant, CCPCA2, was designed. The crystal structure showed Ca(2+) binding in the CCPCA2 mutant and a well ordered cation-binding loop with the full complement of eight protein to cation ligands. Because cation binding to the engineered loop results in diminished CCP activity and destabilization of the essential Trp(191) radical as measured by EPR spectroscopy, these measurements can be used as sensitive methods for determining cation-binding selectivity. Both activity and EPR titration studies show that CCPCA2 binds Ca(2+) more effectively than K(+), demonstrating that an iterative protein engineering-based approach is important in switching protein cation selectivity.


    Organizational Affiliation

    Department of Molecular Biology, Program in Macromolecular Structure, University of California, Irvine, California 92697-3900, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Cytochrome c Peroxidase
A
294Saccharomyces cerevisiae (strain ATCC 204508 / S288c)Gene Names: CCP1 (CCP, CPO)
EC: 1.11.1.5
Find proteins for P00431 (Saccharomyces cerevisiae (strain ATCC 204508 / S288c))
Go to UniProtKB:  P00431
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
K
Query on K

Download SDF File 
Download CCD File 
A
POTASSIUM ION
K
NPYPAHLBTDXSSS-UHFFFAOYSA-N
 Ligand Interaction
HEM
Query on HEM

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Download CCD File 
A
PROTOPORPHYRIN IX CONTAINING FE
HEME
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Work: 0.192 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 107.034α = 90.00
b = 75.458β = 90.00
c = 51.100γ = 90.00
Software Package:
Software NamePurpose
X-PLORrefinement
SCALEPACKdata scaling
X-PLORphasing
X-PLORmodel building

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2002-01-23
    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