Unzipping DNA : A hypothesis on correlation during replication
  Based on the result of an unzipping phase transition by a force in a model of DNA, we hypothesize that the DnaA-type proteins act as a pulling agent with a force slightly less than the critical force for unzipping. The dynamic (space-time) correlation of unzipping then drives the subsequent events of replication. In such a correlation driven scenario, there is no need of a replisome as a structural unit and this elusive replisome may not exist at all. 
Somendra M. Bhattacharjee