Fig. 3.

Mapping the cleavage sites in mRNA IFNA5. a Autoradiogram of human RNase P cleavage of internally radiolabelled (lanes 1–3), 5′- (lanes 4–6) and 3′ end-labelled (lanes 7–9) IFNA5 transcripts, respectively. Lanes 1, 4 and 7 RNA incubated on ice (I); lanes 2, 5 and 8 RNA incubated in reaction buffer (B); lanes 3, 6 and 9 reactions with human RNase P (R). Lane 10 is a molecular weight ladder. Arrows indicate the major digestion products, designated as P1, P3, P5 and P7. b Linear diagram of the IFNA5 substrate transcript (1–700 nt) segmented every 100 nts. Grey areas indicate the protein-coding region and white areas the untranslated flanking regions. The final cleavage products (P1–P7) and (P3–P5) deduced from the observed bands on a 4 % polyacrylamide electrophoresis gel are represented below. c Synechocystis sp. RNase P ribozyme digestion of internally radiolabelled (lanes 2–4), 5′- (lanes 5–7) and 3′ end-labelled (lanes 8–10) IFNA5 transcripts. Lane 1 molecular weight ladder. Lanes 2, 5 and 8 RNA incubated on ice. Lanes 3, 6 and 9 RNA incubated in reaction buffer. Lanes 4, 7 and 10 reactions with Synechocystis sp. ribozyme. Product bands migrating at similar positions as human RNase P product are marked on the right-hand side