Deletion of the cruciform binding domain in CBP/14-3-3 displays reduced origin binding and initiation of DNA replication in budding yeast
1 McGill Cancer Centre, 3655 Promenade Sir William Osler, Montreal, Quebec H3G 1Y6, Canada
2 In memoriam
BMC Molecular Biology 2007, 8:27 doi:10.1186/1471-2199-8-27Published: 12 April 2007
Initiation of eukaryotic DNA replication involves many protein-protein and protein-DNA interactions. We have previously shown that 14-3-3 proteins bind cruciform DNA and associate with mammalian and yeast replication origins in a cell cycle dependent manner.
By expressing the human 14-3-3ε, as the sole member of 14-3-3 proteins family in Saccharomyces cerevisiae, we show that 14-3-3ε complements the S. cerevisiae Bmh1/Bmh2 double knockout, conserves its cruciform binding activity, and associates in vivo with the yeast replication origins ARS307. Deletion of the α5-helix, the potential cruciform binding domain of 14-3-3, decreased the cruciform binding activity of the protein as well as its association with the yeast replication origins ARS307 and ARS1. Furthermore, the mutant cells had a reduced ability to stably maintain plasmids bearing one or multiple origins.
14-3-3, a cruciform DNA binding protein, associates with yeast origins of replication and functions as an initiator of DNA replication, presumably through binding to cruciform DNA forming at yeast replicators.