Proflavine and fidelity of DNA polymerase

With native calf thymus DNA3 as primer and DNA polymerase of E. coli, proflavine (0 × −1 × 10−4 M) inhibited the incorporation of dATP, dCTP, dGTP, and TTP about equally. Using dAT as primer there was inhibition of the rate of synthesis of polynucleotide by proflavine and no more incorporation from dGTP and dCTP than in the absence of the acridine. Nearest-neighbor analysis of the polynucleotide synthesized by DNA polymerase from dATP and TTP showed that sequences of TpT and ApA were formed in the presence of proflavine. Changed sequences were observed whether the reaction was primed with dAT or was unprimed, and the extent of change depended on the concentration of proflavine. The homopolymer dA:dT was identified as one of the products formed.