FIG. 4.

Polysome profile analysis. Cellular extracts were loaded onto 15 to 50% sucrose gradients and centrifuged for 2 h at 275,0000 × g. A continuous A₂₆₀ record for each gradient is presented with the top of the tube on the left. Extracts were prepared from the following: wt, wild-type strain (YBL4164); spb1-2 25°C, the spb1-2 strain (JR4710) grown at the permissive temperature of 25°C; and spb1-2 37°C, the spb1-2 strain grown for 1 h at the nonpermissive temperature of 37°C. The arrows indicate the peaks of 40S, 60S, and 80S subunits and of the half-mer.