There are five different DNA polymerases found in prokaryotes, conveying different functions and specialisms during DNA replication.
DNA polymerase I is used to process Okazaki fragments, as well as base-excision repair. It therefore has a slower rate of 15-20 nucleotides per second. Conserved across all prokaryotes.
DNA polymerase II is a polymerase involved in DNA repair. The number of Pol II enzymes present in the cell is rapidly increased during the SOS response, allowing the upregulation of DNA repair.
DNA polymerase III is the primary 3’ to 5’ polymerase used for daughter strand extension.
DNA polymerase IV / V are error-prone polymerases used in the SOS response and for trans-lesion bypass. These polymerases have a more flexible structure, preventing modified nucleotides from stalling replication. The error can later be rectified using the standard DNA repair pathways.