FIG. 7.

Specificity of binding of PSTVd RNA by EMSA. Radioactively labeled RNAs were incubated with or without purified VIRP1Δ protein for 60 min at room temperature. Mixtures were electrophoresed on 6% native polyacrylamide gels and subjected to autoradiography. When PSTVd RNA (lanes 1 to 3) was incubated with VIRP1Δ protein (lane 2), retardation due to RNA-protein complex formation could be observed, which could be competed for in the presence of 100-fold excess nonlabeled PSTVd RNA (lane 3). In contrast, when other RNA transcripts, e.g., pGEM-3Zf(−) (lanes 4 and 5), potato U1 snRNA (lanes 6 and 7), or pBluescript II KS(+) (lanes 8 and 9), were incubated together with VIRP1Δ (lanes 5, 7, and 9), no such retardation was detected.