Mcm7 ubiquitylation and Pif1-family helicases drive CMG disassembly to preserve genome integrity

Disassembly of the DNA helicase known as CMG (Cdc45-Mcm-GINS) is the key regulated step during DNA replication termination in eukaryotes. In budding yeast, CMG disassembly is initiated by the ubiquitin ligase SCF-Dia2, which ubiquitylates the Mcm7 subunit of CMG, leading to recruitment of the Cdc48 unfoldase. Here we have investigated the partners of the F-box protein Dia2 and tested which ones are dependent upon the TPR domain of Dia2, using yeast strains expressing ProteinA-tagged Dia2 or Dia2∆TPR. Controls include a strain expressing the TAP tag alone, and a strain expressing TAP-tagged Sld5 subunit of the CMG helicase.