FIG. 5.

Expression of Bop1Δ inhibits the generation of 28S rRNA. Clonal cell lines derived from transfection of LAP3 cells with pX11-Bop1Δ (lines 6 and 8), pX11-Bop1 (line 45), or the pX11 vector (line 1-1) were either treated with IPTG (+) for 16 h or left untreated (−). Thereafter, cells were metabolically labeled with [³H]uridine (2.5 μCi/ml) for 30 min and chased in nonradioactive medium for 2 h. In other samples, LAP3 cells were treated with FUrd for 15 min prior to chase. RNA was then isolated, and equal counts per sample were electrophoresed on 1% agarose gel, transferred to a nylon membrane, and visualized by fluorography.