Figure 7.

The expanded, rugged, qualitative energy potential in the Pre-complex. The Post- and Pre-complexes are separated by first-level kinetic barriers. After deacylation of the P-site tRNA, the Pre-complex is able to sample a rugged potential surface. A second-level barrier separates the fluctuating and nonfluctuating conformations, and a third-level barrier further separates the fluctuations between C and Hy1 or C, Hy1, and Hy2. The motions of tRNAs to form A/P state and the P/E state are not coupled.