Bidirectional eukaryotic DNA replication is established by quasi-symmetrical helicase loading.
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Embargo End Date
ICR Authors
Authors
Coster, G
Diffley, JFX
Diffley, JFX
Document Type
Journal Article
Date
2017-07-21
Date Accepted
2017-06-22
Abstract
Bidirectional replication from eukaryotic DNA replication origins requires the loading of two ring-shaped minichromosome maintenance (MCM) helicases around DNA in opposite orientations. MCM loading is orchestrated by binding of the origin recognition complex (ORC) to DNA, but how ORC coordinates symmetrical MCM loading is unclear. We used natural budding yeast DNA replication origins and synthetic DNA sequences to show that efficient MCM loading requires binding of two ORC molecules to two ORC binding sites. The relative orientation of these sites, but not the distance between them, was found to be critical for MCM loading in vitro and origin function in vivo. We propose that quasi-symmetrical loading of individual MCM hexamers by ORC and directed MCM translocation into double hexamers acts as a unifying mechanism for the establishment of bidirectional replication in archaea and eukaryotes.
Citation
Science, 2017, 357 (6348), pp. 314 - 318
Source Title
Science
Publisher
AMER ASSOC ADVANCEMENT SCIENCE
ISSN
0036-8075
eISSN
1095-9203
1095-9203
1095-9203
Collections
Research Team
Genome Replication