Time dependency of [α-32P]ATP, [α-32P]ADP, [α-32P]GTP, [α-32P]UTP, and [α-32P]CTP uptake into intact E. coli cells expressing npt2Ct. (A) Time dependency of [α-32P]ATP (0.8 mM; ●) or [α-32P]ADP (1 mM; ○) uptake. (B) Time dependency of [α-32P]GTP (0.05 mM), [α-32P]UTP (0.5 mM), and [α-32P]CTP (0.5 mM) uptake.