Fig. 3.

Tomato chlorosis virus p22 protects long dsRNA from RNase III-mediated cleavage. A DIG-labeled 562 bp dsRNA was incubated with the p22 (lanes 2, 3 and 4) or S-adenosylhomocysteine hydrolase (SAHH) (lanes 5 and 6) proteins before cleavage by RNase III. The concentrations of proteins are indicated above each lane. The cleavage reaction products were then separated on 1% TBE-agarose gels. As a marker lane, an unlabeled RNA oligonucleotide 22 nt in length was run in parallel, stained with ethidium bromide before the transfer and cut (left). DIG-labeled cleavage reaction products were transferred to nylon membranes and detected using an anti-digoxigenin antibody and a chemiluminescent substrate. Positions of dsRNA precursor and cleavage product are indicated.