FIG 2.

Determination of translational fitness and polysome profile analysis. (A) Measured kinetics of [³⁵S]methionine incorporation into newly synthesized polypeptides, as indicated with arrows. Error bars represent standard deviations obtained from three independent experiments. Inset, translational impairment with respect to the control wild-type cells expressed as 100%, determined based on the slope value for individual graphs. Error bars, standard errors of the mean (SEM) (n = 3); *, P < 0.05 by Student's t test. (B to D) Polysome profile analyses using equal numbers of cells. Each inset shows the following: the total surface area that was calculated for all 40S, 60S, and 80S peaks and four polysomal peaks, the polysome-to-monosome (P/M) ratio that was calculated for each profile by dividing the area of the first four polysomal peaks by the area of the peak for the 80S monosome, and the 40S/60S ratio. All values, i.e., total surface area, P/M ratio, and ratio of individual 40/60 subunits are shown in each panel as means ± SD (n = 3). The sedimentation vector of the ribosomal fractions is indicated by a horizontal arrow, and the optical density value at 254 nm is shown on the y axis; the positions of individual ribosomal subunits are indicated in panel D.