DNA polymerase III is a complex, multichain enzyme responsible for most of the replicative synthesis in bacteria. This DNA polymerase also exhibits 3' to 5' exonuclease activity (By similarity). Serves as a scaffold to help in the dimerization of the core complex. Seems to interact with the delta subunit to transfer the beta subunit on the DNA. a 2'-deoxyribonucleoside 5'-triphosphate + DNA(n) = diphosphate + DNA(n+1) The DNA polymerase holoenzyme is a complex that contains 10 different types of subunits. These subunits are organized into 3 functionally essential subassemblies: the pol III core, the beta sliding clamp processivity factor and the clamp-loading complex. The pol III core (subunits alpha, epsilon and theta) contains the polymerase and the 3'-5' exonuclease proofreading activities. The polymerase is tethered to the template via the sliding clamp processivity factor. The clamp-loading complex assembles the beta processivity factor onto the primer template and plays a central role in the organization and communication at the replication fork. This complex contains delta, delta', psi and chi, and copies of either or both of two different DnaX proteins, gamma and tau. The composition of the holoenzyme is, therefore: (alpha,epsilon,theta)[2]-(isoform:gamma/tau)[3]-delta,delta', psi,chi-beta[4] (By similarity). The production of the two protein products from this region is probably due to programmed ribosomal frameshifting. Produced by full-length translation of the dnaX gene. Probably formed by programmed ribosomal frameshifting to a premature stop codon in the -1 frame at codon 430. Belongs to the DnaX/STICHEL family.