On the fidelity of DNA replication. Lack of primer position effect on the fidelity of mammalian DNA polymerases

Mechanisms for the fidelity of DNA replication in eucaryotes are not adequately understood. Certain hypotheses can be tested by examining whether the first nucleotide inserted is incorporated with a significantly higher error rate than subsequent nucleotides. Using synthetic oligodeoxynucleotides, we have measured the effect of primer position on single-base misinsertion frequencies at an amber site in phi X174 DNA. Our results show a lack of position effect, indicating that processivity and the most direct "energy relay" proofreading mechanisms are not important determinants in eucaryotic replication fidelity.