Predict the effects of the following compounds on intracellular nucleoside triphosphate levels. For each answer, plot percent initial nucleotide level as a function of time after administration of the agent, for each of the four nucleotides (semi-quantitatively). Consider not only the primary effect of the compound but also any indirect effects on allosteric enzymes caused by nucleotide accumulation or depletion.
(a) Effect of thymidine on dNTP levels
(b) Effect of trimethoprim on bacterial rNTP levels
(c) Effect of fluorodeoxyuridine on dNTP levels
(d) Effect of hydroxyurea on dNTP levels