Fig. 3. yrb2 cells are deficient in the levels of the small ribosomal subunit. (A) YRB2⁺ and yrb2 cells were shifted to 15°C for 24 hours, and polysome profiles were resolved in 7-49% sucrose gradients. Abs_254nm was monitored continuously and represents the vertical axis of the profiles. The top of the gradient is on the left-hand side of the profile. The positions of free 40S and 60S subunits, 80S ribosomes, and polysomes are indicated. (B) YRB2⁺ and yrb2 cells were shifted to 15°C for 24 hours, and ribosomal subunit profiles were resolved in 10-35% sucrose gradients.