A CDC6-like factor from the archaea Sulfolobus solfataricus promotes binding of the mini-chromosome maintenance complex 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 hyperthermophilic crenarchaea Sulfolobus solfataricus stimulates binding of the homohexameric 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 understanding how the DNA replication initiation process has evolved in the more complex eukaryotic organisms.