Figure 4

(A) Representative absorbance profile for RNA separated by velocity sedimentation through a 15–60% sucrose gradient. Fractions are numbered from the top to the bottom of the gradient. (B) RNA was extracted from each fraction and subjected to electrophoresis through a formaldehyde gel. The ribosomal RNA distribution profile (25S, 18S and 5S rRNA; indicated by arrowheads) enables the the assignment of OD₂₅₄ peaks, corresponding to the 40S and 60S ribosomal subunits and to intact ribosomes (80S). (C) RT-PCR analysis with hacA primers were performed from each fraction of collected gradients from treated and non-treated cells. The full length hacA^umRNA (arrow) as well as low-molecular-weight version of hacAⁱ(arrowhead) can be visualized.