Analysis of Replication Origin Function on Chromosome III of Saccharomyces cerevisiae

Abstract

Eukaryotic chromosomes contain long linear DNA molecules that initiate replication at multiple sites. Although the chromosomal DNA molecules of the yeast Saccharomyces cerevisiae are two to three orders of magnitude smaller than those of multicellular eu-karyotes, their replication pattern is similar, with active origins spaced at approximately 40-kb intervals (for review, see Newlon 1988) and a regular temporal order of replication (for review, see Fangman and Brewer 1991). An important advantage of yeast in the study of DNA replication is the ability to identify potential chromosomal origins of replication by a simple plasmid assay. These autonomously replicating sequence (ARS) elements act in cis to promote high-frequency transformation and the extrachromosomal maintenance of plasmids (for review, see Campbell and Newlon 1991).