Nucleoside diphosphokinase activity associated with DNA polymerases.

Nucleoside diphosphokinase activity is present in highly purified preparations of DNA polymerase from Micrococcus luteus and Escherichia coli, and in a partially purified DNA polymerase from avian myeloblastosis virus. The activity is also observed in the protein fragment of molecular weight 76,000 that is produced by subtilisin cleavage of DNA polymerase I from E. coli. The NDP kinase activity in DNA polymerase preparations from M. luteus uses various ribo- and deoxyribonucleoside di- and triphosphates as substrates. The presence of this activity in preparations of DNA polymerase results in the apparent use of deoxyribonucleoside diphosphates as substrates for DNA synthesis, provided that some triphosphate is present to serve as a phosphate donor.