Figure 5.

Sucrose gradient analysis of ribosomes from the uL4-Δloop strain grown at different temperatures. Top two rows of gradient traces: cultures of the uL4Δloop and wild-type mutant were harvested after steady state growth at the indicated temperatures. Bottom row: cultures were grown in steady state at 42°, then shifted to 25° for 6 h before harvest. Cultures were diluted as necessary to keep the cell density below ∼10⁸ cells per ml. Whole cell lysates were centrifuged through sucrose gradients in buffer A1.