DNA replication in thermophiles

DNA replication enzymes in the thermophilic Archaea have previously attracted attention due to their obvious use in methods such as PCR. The proofreading ability of the Pyrococcus furiosus DNA polymerase has resulted in a commercially successful product (Pfu polymerase). One of the many notable features of the Archaea is the fact that their DNA processing enzymes appear on the whole to be more like those found in eukaryotes than bacteria. These proteins also appear to be simpler versions of those found in eukaryotes. For these reasons, archaeal organisms make potentially interesting model systems to explore the molecular mechanisms of processes such as DNA replication, repair and recombination.Why archaeal DNA-manipulation systems were adopted over bacterial systems by eukaryotic cells remains a most interesting question that we suggest may be linked to thermophily. The ‘replicon ’ model revisited The process of DNA replication appears to take place in a number of steps that were originally proposed in a model for understanding the regulation of DNA replication in bac-teria. The replicon model proposed by Jacob, Brenner an