1 research outputs found
Mirror-Image Thymidine Discriminates against Incorporation of Deoxyribonucleotide Triphosphate into DNA and Repairs Itself by DNA Polymerases
DNA
polymerases are known to recognize preferably d-nucleotides
over l-nucleotides during DNA synthesis. Here, we report
that several general DNA polymerases catalyze polymerization reactions
of nucleotides directed by the DNA template containing an l-thymidine (l-T). The results display that the 5′–3′
primer extension of natural nucleotides get to the end at chiral modification
site with Taq and Phanta Max DNA polymerases, but the primer extension
proceeds to the end of the template catalyzed by Deep Vent (exo<sup>–</sup>), Vent (exo<sup>–</sup>), and Therminator DNA
polymerases. Furthermore, templating l-nucleoside displays
a lag in the deoxyribonucleotide triphosphate (dNTP) incorporation
rates relative to natural template by kinetics analysis, and polymerase
chain reactions were inhibited with the DNA template containing two
or three consecutive l-Ts. Most interestingly, no single
base mutation or mismatch mixture corresponding to the location of l-T in the template was found, which is physiologically significant
because they provide a theoretical basis on the involvement of DNA
polymerase in the effective repair of l-T that may lead to
cytotoxicity