FIG 7.
Ribosomal transit times depend on RAC/Ssb and Asc1. (A to D) Determination of average ribosomal transit times. [35S]Met incorporation into total protein (nascent chains plus completed polypeptides [filled circles]) and completed polypeptides released from ribosomes (open circles) was determined as described in Materials and Methods. Half average transit times (t1/2) were determined from the displacement in time between the two lines obtained by linear regression analysis. The average transit time is calculated by doubling the difference in the x-axis intercepts of the two lines. For each strain, the experiment was performed in triplicate. The standard error of the mean is given for each experiment. Student's t test was used to calculate P values based on 3 independent experiments: wild type versus Δssb1 Δssb2 strain, P = 0.0012; wild type versus Δasc1 strain, P = 0.0052; Δssb1 Δssb2 strain versus Δasc1 strain, P = 0.00052; Δssb1 Δssb2 strain versus Δssb1 Δssb2 Δasc1 strain, P = 0.0019; Δasc1 strain versus Δssb1 Δssb2 Δasc1 strain, P = 0.0035. Ribosomal transit times in wild-type and Δssb1 Δssb2 Δasc1 strains did not differ significantly.