4XGC

Crystal structure of the eukaryotic origin recognition complex

4XGC の概要

• エントリーDOI: 10.2210/pdb4xgc/pdb
• 分子名称: Origin recognition complex subunit 2, Origin recognition complex subunit 3, Origin recognition complex subunit 5, ... (9 entities in total)
• 機能のキーワード: protein complex, dna binding protein
• 由来する生物種: Drosophila melanogaster (Fruit fly); 詳細
• タンパク質・核酸の鎖数: 7
• 化学式量合計: 277633.77

構造登録者

Bleichert, F.,Botchan, M.R.,Berger, J.M. (登録日: 2014-12-30, 公開日: 2015-04-01, 最終更新日: 2024-11-06)

主引用文献

Bleichert, F.,Botchan, M.R.,Berger, J.M.
Crystal structure of the eukaryotic origin recognition complex.
Nature, 519:321-326, 2015

PubMed Abstract: Initiation of cellular DNA replication is tightly controlled to sustain genomic integrity. In eukaryotes, the heterohexameric origin recognition complex (ORC) is essential for coordinating replication onset. Here we describe the crystal structure of Drosophila ORC at 3.5 Å resolution, showing that the 270 kilodalton initiator core complex comprises a two-layered notched ring in which a collar of winged-helix domains from the Orc1-5 subunits sits atop a layer of AAA+ (ATPases associated with a variety of cellular activities) folds. Although canonical inter-AAA+ domain interactions exist between four of the six ORC subunits, unanticipated features are also evident. These include highly interdigitated domain-swapping interactions between the winged-helix folds and AAA+ modules of neighbouring protomers, and a quasi-spiral arrangement of DNA binding elements that circumnavigate an approximately 20 Å wide channel in the centre of the complex. Comparative analyses indicate that ORC encircles DNA, using its winged-helix domain face to engage the mini-chromosome maintenance 2-7 (MCM2-7) complex during replicative helicase loading; however, an observed out-of-plane rotation of more than 90° for the Orc1 AAA+ domain disrupts interactions with catalytic amino acids in Orc4, narrowing and sealing off entry into the central channel. Prima facie, our data indicate that Drosophila ORC can switch between active and autoinhibited conformations, suggesting a novel means for cell cycle and/or developmental control of ORC functions.

PubMed: 25762138
DOI: 10.1038/nature14239

実験手法

X-RAY DIFFRACTION (3.5 Å)