Figure 4.

Secondary structures of Citrus viroid III clone CVd‐III.072 (A), Citrus bent leaf viroid clone CBLVd.032 (B), Hop stunt viroid clone HSVd.cit106 (C) and Citrus viroid IV clone CVd‐IV (D) as determined by integration of the SHAPE data into the RNAstructure software. The colours are attributed according to the relative SHAPE intensities (black ≤ 0.3, 0.3 < blue < 0.5, 0.5 ≤ orange < 0.7, 0.7 ≤ red). T_L (Terminal Left), P (Pathogenicity), C (Central), V (Variable) and T_R (Terminal Right) refer to the structural domains defined elsewhere (Ashulin et al., 1991; Francis et al., 1995; Stasys et al., 1995), except for CVd‐IV, which was defined in this study by comparing its structure with those of other members of the Pospiviroidae family. The A motif on each structure is indicated by a box.