Pyridone-based nucleotide analogues accepted for DNA biosynthesis

Novel pyridone-based nucleotides were investigated for maintenance of DNA synthesis, carried on by representatives of different classes of polymerases. Five different nucleoside triphosphates of similar structure were addressed, demonstrating involvement in primer extension. The  nucleotides containing 4-chloro- and 4-bromo-2-pyridone as a nucleobase were preferred by all DNA polymerases tested. These nucleotides were incorporated up to several instances in a  row and unexpectedly failed to ensure DNA primer termination. Temporary polymerase stalling obeys kinetic constrain and is alleviated by availability of nucleotides readily acquired by the polymerase. Lack of inhibitory properties of 2-pyridone nucleobase confirms the processivity of DNA polymerases challenged by incorporated nucleotides.