2',3'-Dideoxyadenosine 5'-triphosphate (ddATP) is an in vitro inhibitor of reverse transcriptases from retroviruses, including HIV-1 and visna (Kis = 20 and 37 nM, respectively). It also blocks, in vitro, mammalian and bacterial DNA polymerases. ddATP, produced intracellularly by the phosphorylation of exogenously supplied 2’,3’-dideoxyadenosine, competes with dATP, resulting in chain termination. Because of this activity, dideoxynucleoside 5’-triphosphates, including ddATP, are used to terminate chain extension produced by the Taq polymerase used in polymerase chain reactions. It is also an antagonist of the purinergic receptor P2X2/3 (pIC50 = 6.5).
