-dehydrothymidine 5'-triphosphate (dddTTP) shows termination substrate properties in the DNA synthesis catalyzed by E. coli DNA polymerase I KF, rat liver DNA polymerase r, reverse transcriptases of avian myeloblastosis virus and Raus sarcoma virus and calf thymus terminal deoxynucleotidyl transferase. This implies that the mononucleotide residue of dddTTP incorporates into 3'-termini of newly synthesized DNA chains. However, dddTTP has no influence on the DNA synthesis catalyzed by calf thymus DNA polymerase ct. In the case of some DNA polymerases dddTTP was one order of magnitude more effective in comparison with the other known termination substrates.
It is demonstrated here that rat liver DNA polymerase /I catalyzes the pyrophosphorolysis reaction with pyrophosphate (PP<) and its analogues. The substrate specificity of the PPi-binding site of several DNA polymerases was investigated. It was discovered that the ability of DNA polymerases to utilize PPi analogues instead of PPi in the pyrophosphorolysis reaction was markedly restricted. Only imidodiphosphate and methylenediphosphonate were demonstrated as participating in this process. Oxodiphosphonate and phosphonoformate inhibited DNA synthesis, but probably not via the interaction with the PPi-binding site of DNA polymerases.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.