FIG. 3.

In vitro binding of HBV RT proteins to ɛ RNA mutants with the apical loop but not the internal bulge deleted. Two different RT proteins were tested for their binding to the wild-type (long), lower-stem-shortened (short), bulge deletion (dB), or loop deletion (dL) ɛ RNA, as described in the legend to Fig. 2. The RNA mutants are schematized in the secondary-structure model. Deletions are denoted by dotted lines. The symbol * indicates a minor structural isoform detected sometimes in the free RNA, as reported before (21).