Figure 5.

Kinetics of NAc-Phe-tRNA^Phe translocation with varying temperature and concentrations of EF-G and Mg²⁺

The kinetics of the mRNA movement during translocation was followed in stopped-flow, where EF-G was rapidly mixed to a NAc-Phe-tRNA^Phe containing pre-T complex (0.5 µM). The left panels show the pyrene fluorescence traces monitored with 360 nm long-pass filter (343 nm excitation). The right panels present the rates and amplitudes of the fast phase of the fluorescence traces (Table 2). The plots represent measurements with varying concentration of EF-G (A, B), different temperature (C, D) and varying Mg²⁺ concentration (E, F). The rates and the fractional amplitude of the fast phase are summarized in Table 2.