Excision repair and DNA synthesis with a combination of HeLa DNA polymerase beta and DNase V.

摘要: The ability of HeLa DNA polymerases to carry out synthesis from incisions made by various endodeoxyribonucleases which recognize or form baseless sites in was examined. polymerase beta carried limited strand displacement 3'-hydroxyl nucleotide termini apurinic/apyrimidinic (AP) endonuclease II at the 5'-side apurinic sites. Escherichia coli III incises 3'-side produce nicks with 3'-deoxyribose did not efficiently support beta-polymerase. However, these could be activated AP II, an enzyme removes sugar phosphate 3'-termini, thus creating a one-nucleotide gap. With dGTP as only nucleoside triphosphate present, beta-polymerase catalyzed repair those gaps lacked dGMP. In contrast, alpha unreactive all above incised substrates. Larger patches were produced nick translation and DNase V. Moreover, E. V removed termini. also stimulated both rate extent incisions. this case 5'-termini, translational occurred. Complete excision pyrimidine dimers achieved beta-polymerase, V, ligase UV-irradiated T4 UV II. Such gap containing 5'-thymine: thymidylate cyclobutane dimer primarily dinucleotide then promotes synthesis.