Some selected amino acids, in particular L-aspartic acid (L-Asp) and L- histidine (L-His), can function as leaving group during polymerase-catalyzed incorporation of deoxyadenosine monophosphate ( dAMP) in DNA. Although L- Asp-dAMP and L-His-dAMP bind, most probably, in a different way in the active site of the enzyme, aspartic acid and histidine can be considered as mimics of the pyrophosphate moiety of deoxyadenosine triphosphate. L- Aspartic acid is more efficient than D-aspartic acid as leaving group. Such P-N conjugates of amino acids and deoxynucleotides provide a novel experimental ground for diversifying nucleic acid metabolism in the field of synthetic biology.