MTH1 hydrolyzes oxidized nucleotide triphosphates, thereby preventing them from being incorporated into DNA.
Incorporation of the nucleobases into DNA and RNA oligomers is achieved either chemically using building blocks such as nucleoside phosphoramidites or enzymatically using nucleotide triphosphates.
Nucleotide 3, which differs from 1 only in that it lacks the etheno group, non-complementary nucleotide triphosphates, and related monophosphates and nucleosides, are completely inactive as inhibitors of reverse transcriptase at concentrations up to 1 mM.
Another important observation that may also help to explain this apparent discrepancy is the finding that IDE can be activated not only by nucleotide triphosphates, but also by inorganic triphosphate (PPPi) alone [24], [29].
One very important aspect to consider is the fact that nucleotide triphosphates in an aqueous solution will spontaneously hydrolyze with first-order reaction kinetics [5].
With the selective pressure of mutation removed, we can also directly observe the impact of the penalty on reverse polymerizing organisms due to spontaneous hydrolysis of nucleotide triphosphates.
Ecto-nucleotide pyrophosphatase/phosphodiesterases (NPPs) hydrolyse nucleotide triphosphates to the corresponding nucleotide monophosphates and the mineralisation inhibitor, pyrophosphate (PPi).
However, biotin labeling is a preferred option, as biotin-ligated nucleotide triphosphates are commercially available.
Furthermore, nucleotide triphosphates with attached ligands other than biotin can also be used.
Here, again, it would be instructive to test unwinding with the nucleotide triphosphates.
