Polymerases are present in prokaryotes and eukaryotes, where they are essential to the manufacture of genetic material.

DNA polymerase functions to duplicate DNA (deoxyribonucleic acid). This process is called replication. Each time a cell divides, DNA polymerase duplicates its entire DNA, and the cell passes one copy to each daughter cell. This process ensures that genetic material is faithfully passed from generation to generation. DNA polymerase is extremely accurate in its task. Its error rate is less than one base in each billion duplicated.

The task of DNA replication requires a number of polymerases. Three distinct DNA polymerases (I, II, and III) have been isolated from Escherichia coli. Arthur Kornberg discovered the first DNA polymerase (I) in E. coli in 1956. Studies of mutant strains of E. coli led to the discovery of the other DNA polymerases II and III in the 1970s...