2O7M

The C-terminal loop of the homing endonuclease I-CreI is essential for DNA binding and cleavage. Identification of a novel site for specificity engineering in the I-CreI scaffold


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.184 
  • R-Value Observed: 0.186 

wwPDB Validation   3D Report Full Report


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Literature

The C-terminal loop of the homing endonuclease I-CreI is essential for site recognition, DNA binding and cleavage

Prieto, J.Redondo, P.Padro, D.Arnould, S.Epinat, J.C.Paques, F.Blanco, F.J.Montoya, G.

(2007) Nucleic Acids Res 35: 3262-3271

  • DOI: 10.1093/nar/gkm183
  • Primary Citation of Related Structures:  
    2O7M

  • PubMed Abstract: 
  • Meganucleases are sequence-specific endonucleases with large cleavage sites that can be used to induce efficient homologous gene targeting in cultured cells and plants. These enzymes open novel perspectives for genome engineering in a wide range of fields, including gene therapy ...

    Meganucleases are sequence-specific endonucleases with large cleavage sites that can be used to induce efficient homologous gene targeting in cultured cells and plants. These enzymes open novel perspectives for genome engineering in a wide range of fields, including gene therapy. A new crystal structure of the I-CreI dimer without DNA has allowed the comparison with the DNA-bound protein. The C-terminal loop displays a different conformation, which suggests its implication in DNA binding. A site-directed mutagenesis study in this region demonstrates that whereas the C-terminal helix is negligible for DNA binding, the final C-terminal loop is essential in DNA binding and cleavage. We have identified two regions that comprise the Ser138-Lys139 and Lys142-Thr143 pairs whose double mutation affect DNA binding in vitro and abolish cleavage in vivo. However, the mutation of only one residue in these sites allows DNA binding in vitro and cleavage in vivo. These findings demonstrate that the C-terminal loop of I-CreI endonuclease plays a fundamental role in its catalytic mechanism and suggest this novel site as a region to take into account for engineering new endonucleases with tailored specificity.


    Organizational Affiliation

    Spanish National Cancer Center (CNIO), Structural Biology and Biocomputing Programme, NMR Group and Macromolecular Crystallography Group, c/Melchor Fdez. Almagro 3, 28029-Madrid, Spain.



Macromolecules
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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
DNA endonuclease I-CreIA, B156Chlamydomonas reinhardtiiMutation(s): 0 
EC: 3.1
UniProt
Find proteins for P05725 (Chlamydomonas reinhardtii)
Explore P05725 
Go to UniProtKB:  P05725
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.184 
  • R-Value Observed: 0.186 
  • Space Group: P 43
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 69.088α = 90
b = 69.088β = 90
c = 93.04γ = 90
Software Package:
Software NamePurpose
REFMACrefinement

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2007-10-23
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance