Figure 2. Probing RNA structure conservation among the subtypes. The original SHAPE-directed model (left) is compared with the mfold prediction for the subtype B isolate NL4-3 and the prototype sequence of subtypes A, B, C and D. Sequence differences compared with the NL4-3 sequence are highlighted in black. Structural conservation is illustrated for POL3, partial conservation for motif M and a lack of conservation for motif B. See Table 1 for more details. Single-stranded RNA segments that lack mutations compared with the NL4-3 sequence are indicated as Nx, with x indicating the number of nucleotides.