A Cdc6-like factor from the archaeon sulfolobus solfataricus promotes binding of MCM to DNA

The archaeal replication apparatus appears to be a simplified version of the eukaryotic one with fewer polypeptides and simpler protein complexes. Herein, we report evidence that a Cdc6-like factor from the hyper-thermophilic crenarchaeon Sulfolobus solfataricus stimulates binding of the homo-hexameric MCM-like complex to bubble- and fork-containing DNA oligonucleotides that mimic early replication intermediates. This function does not require the Cdc6 ATP- and DNA-binding activities. These findings may provide important clues to understand how the DNA replication initiation process has evolved in the more complex eukaryotic organisms.