The Saccharomyces cerevisiae origin recognition complex (ORC) binds to replication origins at the ARS consensus sequence (ACS), serving as a scaffold for the assembly of replication complexes needed for the initiation of DNA synthesis. I generated a genome-wide map of nucleosome positions surrounding replication origins because the precise locations of nucleosomes may influence replication. My map revealed a nucleosome-free region surrounding the ACS that is bordered by two well-positioned nucleosomes. I was able to explain differences in origin properties by clustering nucleosome profiles. I found an association between the replication time and nucleosome profile for a given origin cluster. An ORC depletion mutant nucleosome map indicated a shift in nucleosomes towards the ACS. I present the first genome-wide view of origin nucleosome architecture, indicate a relationship between chromatin structure and replication timing, and suggest a model whereby the interplay between DNA sequence and ORC binding defines the nucleosome occupancy pattern.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OTU.1807/30002 |
| Date | 13 October 2011 |
| Creators | Berbenetz, Nicolas Matthew |
| Contributors | Nislow, Corey, Brown, Grant |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
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