Deoxynucleoside Triphosphate Containing Pyridazin-3-one Aglycon as a Thymidine Triphosphate Substitute for Primer Extension and Chain Elongation by Klenow Fragments.

Deoxynucleoside 5'-triphosphate was synthesized with 3-oxo-2 H-pyridazin-6-yl (Pz)-a uracil analogue lacking a 2-keto group-as the nucleobase. Theoretical analyses and hybridization experiments indicated that Pz recognizes adenine (A) for formation of a Watson-Crick base pair. Primer extension reactions using nucleoside 5'-triphosphate and the Klenow fragment revealed that the synthetic nucleoside 5'-triphosphate was incorporated into the 3' end of the primer through recognition of A in the template strand.

7-(Benzofuran-2-yl)-7-deazadeoxyguanosine as a fluorescence turn-ON probe for single-strand DNA binding protein.

7-(Benzofuran-2-yl)-7-deazadeoxyguanosine ((BF)dG) was synthesized and incorporated into an oligodeoxynucleotide (ODN). The single-stranded ODN containing (BF)dG shows 91-fold fluorescence enhancement upon binding of single-strand DNA binding protein.