Figure 1.

Effect of thiostrepton on EF-G-dependent GTP hydrolysis on the ribosome. (a) Incubation at 20°C. The reaction was performed with EF-G (0.4 μM), [γ-³²P]GTP (5 μM), and vacant ribosomes (0.4 μM) with or without thiostrepton (100 μM). (b) Incubation at 37°C, otherwise as in a. (c) Incubation at 37°C with catalytic amounts of EF-G (0.02 μM) and ribosomes (0.2 μM), otherwise as in a. ○, In the absence of antibiotic; ●, in the presence of thiostrepton; ▵, control without EF-G; ▿, control without ribosomes. Reactions were analyzed by TLC.