Your browser version may not work well with NCBI's Web applications. More information here...
1: Science. 1993 Dec 17;262(5141):1838-44.
Related Articles, Links
Click here to read
Comment in:
Origin recognition complex (ORC) in transcriptional silencing and DNA replication in S. cerevisiae.

Foss M, McNally FJ, Laurenson P, Rine J.

Department of Molecular and Cellular Biology, University of California, Berkeley 94720.

In Saccharomyces cerevisiae, the HMR-E silencer blocks site-specific interactions between proteins and their recognition sequences in the vicinity of the silencer. Silencer function is correlated with the firing of an origin of replication at HMR-E. An essential gene with a role in transcriptional silencing was identified by means of a screen for mutations affecting expression of HMR. This gene, known as ORC2, was shown to encode a component of the origin recognition complex that binds yeast origins of replication. A temperature-sensitive mutation in ORC2 disrupted silencing in cells grown at the permissive temperature. At the restrictive temperature, the orc2-1 mutation caused cell cycle arrest at a point in the cell cycle indicative of blocks in DNA replication. The orc2-1 mutation also resulted in the enhanced mitotic loss of a plasmid, suggestive of a defect in replication. These results provide strong evidence for an in vivo role of ORC in both chromosomal replication and silencing, and provide a link between the mechanism of silencing and DNA replication.

Publication Types:
PMID: 8266071 [PubMed - indexed for MEDLINE]