Fig. 2. snR190 functions in pre-60S r-particle maturation.

a Accumulation levels of rRNA precursors in W303 wild-type (WT) and snr190-[mut.C] strains. Total RNA extracted from two independent clones (#1 and #2) for each strain was analyzed by northern blotting. The RNA molecules detected using radiolabeled oligonucleotide probes (Supplementary Table 4) are indicated on the left. b Accumulation levels of rRNA precursors in W303 snr190-[mut.C] strain and upon ectopic re-expression of snR190. Total RNA extracted from two independent clones (#1 and #2) of strain W303 snr190-[mut.C] transformed with a vector rescuing snR190 expression (SNR190-U14) or the corresponding empty vector as control (E.V.) was analyzed by northern blotting. The same probes as in a were used. c Polysome profiles on sucrose gradients of wild-type (green) and snr190-[mut.C] (red) strains in the W303 background. Total cellular extracts prepared from these strains were centrifuged through 10–50% sucrose gradients. A₂₅₄ was measured during gradient fractionation. The identity of the different peaks is indicated and half-mers are marked with arrows. d Polysome profiles on sucrose gradients of W303 snr190-[mut.C] strain transformed with an empty vector (E.V., red) or upon ectopic re-expression of snR190 (SNR190-U14, purple). Total cellular extract preparation and analysis were carried out as in c.