Figure 6.

Polysomal Association of rnc3/4 rRNA Precursors.

Polysomes were fractionated through a 15 to 55% sucrose step gradient as described in Methods. Total RNA from the 12 fractions collected was analyzed by RNA gel blot with dsDNA probes as indicated at right. Probe locations are found in Figure 2 (trnA-23S int., probe A; 23S rRNA, probe C; 23S-4.5S int., probe E), Figure 3 (4.5S, probe A), and Figure 4 (16S, probe A). Transcript sizes are shown at left, and precursors are marked by asterisks at right. Representative ethidium bromide (EtBr)-stained gels are shown to represent loading. The free ribosomal fractions (<80S; lanes 1 to 6) and polysomal fractions (lanes 7 to 12) were determined using a puromycin control (bottom) as described in the text.