2ex5
From Proteopedia
Group I Intron-encoded Homing Endonuclease I-CeuI Complexed With DNA
Overview
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.
About this Structure
2EX5 is a Single protein structure of sequence from Chlamydomonas eugametos. Full crystallographic information is available from OCA.
Reference
The structure of I-CeuI homing endonuclease: Evolving asymmetric DNA recognition from a symmetric protein scaffold., Spiegel PC, Chevalier B, Sussman D, Turmel M, Lemieux C, Stoddard BL, Structure. 2006 May;14(5):869-80. PMID:16698548 Page seeded by OCA on Sun May 4 03:12:49 2008
