Sites of termination ofin vitroDNA synthesis oncis-diamminedichloroplatinum(II) treated single-stranded DNA: a comparison betweenE.coliDNA polymerase I and eucaryotic DNA polymerases α

Abstract

We have compared the capacity of the large fragment of E. coli DNA polymerase I and highly purified DNA polymerases .alpha. from either Drosophila melanogaster embryos or calf thymus to replicate single-stranded M13 mp10 DNA treated with the antitumoral drug cis-diamminedichloroplatinum(II) (cis-DDP). We report that: a) although prokaryotic and eukaryotic enzymes have different structural complexity and dissimilar in vivo functions, their synthesis was blocked in vitro at similar sites on cis-DDP treated DNA; b) this inhibition occurred not only at d(G)n sequences, as previously reported for E. coli DNA polymerase I, (Pinto and Lippared (1985) Proc. Natl. Acad. Sci. USA, 82, 46160-4619) but also at other sequences which may represent putative cis-DDP-DNA adducts.