The Origin Recognition Complex Interacts with a Subset of Metabolic Genes Tightly Linked to Origins of Replication
(A) Examples, from the ChIP–on–chip data, of an orc2-1-sensitive ORC peak at a replication origin, ARS820, and of a nearby orc2-1-resistant ORF–ORC peak at the ENO2 gene. (B) Immunoprecipitation with a cocktail of monoclonal antibodies against Orc1p, Orc2p, and Orc3p resulted in a slight enrichment of the ENO2 ORF relative to a background locus (FKH1), while immunoprecipitation with a cocktail of two monoclonal Sir3 antibodies did not result in any enrichment of ENO2. On the other hand, the Sir3 antibodies, similarly to the ORC antibodies, were able to efficiently immunoprecipitate HMR. (C) ChIPs with an anti–HA antibody were performed in Orc2-3xHA and untagged strains. Association of the antibody with two different ORF-ORC loci, ENO2 and TDH3, as well as an origin of replication, ARS820, was dependent on the presence of HA–tagged Orc2. All data were normalized to immunoprecipitated FKH1 from the same sample. Averages of two biological replicates of each strain are plotted, with error bars representing one standard deviation.