The Origin Recognition Complex Interacts with a Subset of Metabolic Genes Tightly Linked to Origins of Replication
The diagram shows expected migration patterns of different replication intermediates (replication bubbles and forks) on 2D gels. The ratio of bubbles to small forks corresponds to origin efficiency. Restriction enzyme and probe positions (black rectangles) are shown. The two “confirmed” origins, ARS731.5 and ARS820, are orc2-1-sensitive (with orc2-1/WT ratios of 0.36 and 0.35, respectively), corresponding to a decrease in firing at these sites in the orc2-1 mutant. Both ORF–ORC sites, TDH3 and ENO2, have been detected as sites of ORC and MCM binding in another ChIP–based study  and are annotated as “likely” ARSs by OriDB. In the figure, dashed ovals indicate “likely” ARS boundaries. Both “likely” ARSs at TDH3 and ENO2 are orc2-1-resistant (orc2-1/WT ratios of 1.1 for each), but neither one produced replication bubbles either in the wild-type or in the orc2-1 strain. Gray bars indicate chromosomal clones tested in plasmid origin assays (Table 1, Table S3).