Figure 2. Effects of ATP on NRTI action.

A. Effects of ATP on AZTTP-dependent inhibition of RT activities. The dTMP incorporation into poly (rA)·p(dT)_12-18 was measured using [α-³²P]dTTP and purified p51/p66 heterodimers in the presence of the indicated concentrations of ATP and AZTTP. Ratios of the dTTP incorporation at given concentrations of AZTTP to that in the absence of AZTTP are shown. B. Effects of nucleotides and related compounds on IC₅₀s of AZTTP. IC₅₀s of AZTTP were determined in the presence of 5 mM of the indicated compounds, and the fold increases in IC₅₀ compared to AZTTP without the compounds are shown. C. A simplified kinetics model of DNA polymerization in the presence of ATP and NRTI. The model was generated on the basis of the kinetics data in Figure 1 and Figure S2, previously reported kinetics data [17], [18], and a crystal structure study of the ATP-RT complex [11]. D. Effects of ATP on the K_i values of AZTTP and d4TTP. The K_i^AZTTP and K_i^d4TTP values were estimated by fitting the initial velocity of dTTP incorporation to Equation 5 as described in Materials and Methods. The mean values with variances are shown for two independent experiments performed with duplicate samples.