The CMG complex composed of Mcm2-7, Cdc45 and GINS is postulated to be the eukaryotic replicative DNA helicase, whose activation requires sequential recruitment of replication proteins onto Mcm2-7. Current models suggest that Mcm10 is involved in assembly of the CMG complex, and in tethering of DNA polymerase α at replication forks. Here, we report that Mcm10 is required for origin DNA unwinding after association of the CMG components with replication origins in fission yeast. A combination of promoter shut-off and the auxin-inducible protein degradation (off-aid) system efficiently depleted cellular Mcm10 to <0.5% of the wild-type level.
Depletion of Mcm10 did not affect origin loading of Mcm2-7, Cdc45 or GINS, but impaired recruitment of RPA and DNA polymerases.
Mutations in a conserved zinc finger of Mcm10 abolished RPA loading after recruitment of Mcm10. These results show that Mcm10, together with the CMG components, plays a novel essential role in origin DNA unwinding through its zinc-finger function.
2012-05-03
Eng.
The EMBO journal
Department of Biological Sciences, Graduate School of Science, Osaka University, Osaka, Japan.
EMBO J. 2012 May;31(9):2182-94
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