2EX5 image
Entry Detail
PDB ID:
2EX5
Keywords:
Title:
Group I Intron-encoded Homing Endonuclease I-CeuI Complexed With DNA
Biological Source:
PDB Version:
Deposition Date:
2005-11-07
Release Date:
2006-05-23
Method Details:
Experimental Method:
Resolution:
2.20 Å
R-Value Free:
0.23
R-Value Work:
0.21
R-Value Observed:
0.21
Space Group:
P 21 21 21
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:DNA endonuclease I-CeuI
Mutations:Q93R
Chain IDs:C (auth: A), D (auth: B)
Chain Length:207
Number of Molecules:2
Biological Source:Chlamydomonas eugametos
Polymer Type:polydeoxyribonucleotide
Description:I-CeuI DNA target site
Chain IDs:A (auth: X)
Chain Length:26
Number of Molecules:1
Biological Source:synthetic construct
Polymer Type:polydeoxyribonucleotide
Description:I-CeuI DNA target site, complementary strand
Chain IDs:B (auth: Y)
Chain Length:26
Number of Molecules:1
Biological Source:synthetic construct
Ligand Molecules
Primary Citation
The structure of I-CeuI homing endonuclease: Evolving asymmetric DNA recognition from a symmetric protein scaffold.
Structure 14 869 880 (2006)
PMID: 16698548 DOI: 10.1016/j.str.2006.03.009

Abstact

Homing endonucleases are highly specific catalysts of DNA strand breaks, leading to the transfer of mobile intervening sequences containing the endonuclease ORF. We have determined the structure and DNA recognition behavior of I-CeuI, a homodimeric LAGLIDADG endonuclease from Chlamydomonas eugametos. This symmetric endonuclease displays unique structural elaborations on its core enzyme fold, and it preferentially cleaves a highly asymmetric target site. This latter property represents an early step, prior to gene fusion, in the generation of asymmetric DNA binding platforms from homodimeric ancestors. The divergence of the sequence, structure, and target recognition behavior of homing endonucleases, as illustrated by this study, leads to the invasion of novel genomic sites by mobile introns during evolution.

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Primary Citation of related structures