Figure 3.

Characterization of radioactively 5′-³²P labeled 29-nt VS substrate 23. The gel compares ligated substrates containing a 5′-oxygen (O) or a 5′-sulfur (S) at the cleavage site. The samples in the last three lanes of the input, alkaline hydrolysis and RNase T1 sections were irradiated with UV light (hν) for 5 min before loading (inputs) or before exposing the sample to alkaline conditions or RNase T1. Samples treated with silver nitrate are shown at the far right of the gel.