InterPro domain: IPR021110

Genome duplication is precisely regulated by cyclin-dependent kinases CDKs, which bring about the onset of S phase by activating replication origins and then prevent relicensing of origins until mitosis is completed. The optimum sequence motif for CDK phosphorylation is S/T-P-K/R-K/R, and Drc1-Sld2 is found to have at least 11 potential phosphorylation sites. Drc1 is required for DNA synthesis and S-M replication checkpoint control. Drc1 associates with Cdc2 and is phosphorylated at the onset of S phase when Cdc2 is activated. Thus Cdc2 promotes DNA replication by phosphorylating Drc1 and regulating its association with Cut5 [ 1 ]. Sld2 and Sld3 represent the minimal set of S-CDK substrates required for DNA replication [ 2 ].

This entry also includes ATP-dependent DNA helicase Q4, which may be involved in chromosome segregation and has been associated with various diseases.

1. CDK phosphorylation of Drc1 regulates DNA replication in fission yeast. Curr. Biol. 12, 599-605
2. CDK-dependent phosphorylation of Sld2 and Sld3 initiates DNA replication in budding yeast. Nature 445, 328-32