2PFJ

Crystal Structure of T7 Endo I resolvase in complex with a Holliday Junction

2PFJ の概要

• エントリーDOI: 10.2210/pdb2pfj/pdb
• 関連するPDBエントリー: 1FZR 1M0D 1M0I
• 分子名称: 27-MER, Endodeoxyribonuclease 1, CALCIUM ION, ... (4 entities in total)
• 機能のキーワード: hydrolase, holliday junction resolvase, homodimer, domain swapped, composite active site, hydrolase-dna complex, hydrolase/dna
• 由来する生物種: Enterobacteria phage T7
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 52257.35

構造登録者

Hadden, J.M.,Declais, A.C.,Carr, S.B.,Lilley, D.M.,Phillips, S.E. (登録日: 2007-04-05, 公開日: 2007-10-30, 最終更新日: 2023-08-30)

主引用文献

Hadden, J.M.,Declais, A.C.,Carr, S.B.,Lilley, D.M.,Phillips, S.E.
The structural basis of Holliday junction resolution by T7 endonuclease I.
Nature, 449:621-624, 2007

PubMed Abstract: The four-way (Holliday) DNA junction is the central intermediate in homologous recombination, a ubiquitous process that is important in DNA repair and generation of genetic diversity. The penultimate stage of recombination requires resolution of the DNA junction into nicked-duplex species by the action of a junction-resolving enzyme, examples of which have been identified in a wide variety of organisms. These enzymes are nucleases that are highly selective for the structure of branched DNA. The mechanism of this selectivity has, however, been unclear in the absence of structural data. Here we present the crystal structure of the junction-resolving enzyme phage T7 endonuclease I in complex with a synthetic four-way DNA junction. Although the enzyme is structure-selective, significant induced fit occurs in the interaction, with changes in the structure of both the protein and the junction. The dimeric enzyme presents two binding channels that contact the backbones of the junction's helical arms over seven nucleotides. These interactions effectively measure the relative orientations and positions of the arms of the junction, thereby ensuring that binding is selective for branched DNA that can achieve this geometry.

PubMed: 17873858
DOI: 10.1038/nature06158

実験手法

X-RAY DIFFRACTION (3.1 Å)