Involvement of two protein factors and ATP in in vitro DNA synthesis catalyzed by DNA polymerase 3 of Escherichia coli.

The in vitro conversion of single-stranded DNA from bacteriophage fd to duplex structures depends on E. coli RNA polymerase, DNA polymerase III, riboand deoxyribonucleoside triphosphates, Mg(+2), spermidine or DNA-unwinding protein of E. coli, and two additional protein factors, referred to here as Factors I and II. These two factors are also essential for dTMP incorporation catalyzed by DNA polymerase III and dependent on poly(dA).oligo(dT) primer-template. In the latter reaction, there is an absolute dependency on ATP or dATP.