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Yeast origin recognition complex functions in transcription silencing and DNA replication
S P Bell1, R Kobayashi, B Stillman
1Cold Spring Harbor Laboratory, NY 11724.
Science (New York, N.Y.)
|December 17, 1993
Summary
The Saccharomyces cerevisiae origin recognition complex (ORC) is crucial for DNA replication initiation. ORC binds to DNA replication origins and mating-type silencers, suggesting a dual role in replication and transcriptional domain determination.
Area of Science:
- Molecular Biology
- Yeast Genetics
- DNA Replication
Background:
- The origin recognition complex (ORC) is essential for DNA replication.
- Its precise functions in yeast Saccharomyces cerevisiae are under investigation.
Purpose of the Study:
- To isolate genes encoding ORC subunits.
- To characterize the role of the ORC2 subunit in DNA replication and transcriptional silencing.
Main Methods:
- Gene isolation and characterization.
- Analysis of temperature-sensitive mutations in ORC2.
- DNA binding assays.
- Investigation of transcriptional silencing.
Main Results:
- Genes for two ORC subunits were isolated.
- A mutation in ORC2 (orc2ts) affects early DNA replication.
- ORC from orc2ts cells shows defective DNA binding.
- ORC binds specifically to yeast mating-type silencers.
Conclusions:
- ORC functions early in DNA replication initiation at yeast origins.
- ORC is involved in establishing transcriptional domains, likely through binding to silencers.