The Origin Recognition Complex Interacts with a Subset of Metabolic Genes Tightly Linked to Origins of Replication
(A) ORC binding to HMR-E in vivo is orc2-1-resistant. ORC ChIPs were performed in the ORC2 and orc2-1 strains at the permissive temperature of 23°C, and relative enrichment of HMR-E- or ARS1-containing DNA fragments was measured by PCR. ADH4 signal was used as a measure of background ORC binding. (B) The majority of sites identified in our ORC ChIP–on–chip have already been annotated by the Origin Database, validating our identification of bona fide ORC sites. (C) Novel ORC sites form an orc2-1-resistant, ORF–overlapping cluster. Each ORC peak that overlapped at least one ORF was included in the calculation outlined the diagram. Dmax was calculated as described in the text and plotted against orc2-1/WT ratio. ORC peaks in the graph are classified according to their OriDB annotations. “Novel” sites are those identified for the first time in this study as ORC–binding sites.