RNA/DNA Polymerase Inhibitors

DNA polymerases cannot initiate de novo DNA synthesis; they require a primer, formed by the enzyme primase. DNA polymerases are unidirectional and can only elongate DNA chains in a 5' to 3' direction. A unique feature of some of these enzymes is their 'proofreading' ability. DNA polymerases I, II and III have 3' to 5' exonuclease activity and they can remove incorrectly newly incorporated nucleotides. This makes the error rate during DNA replication very low, hence maintaining the integrity of the genome.