(A) SHAPE-guided and alternative folds for the PRTE in PEMV1. Relative SHAPE reactivities of individual nucleotides are colour-coded (see key) in the SHAPE-guided fold (left). The CP stop codon, SL1, and SL3 are labeled. An alternative fold in which SL2 forms is shown on the right, with a double-headed arrow depicting the proposed interconversion between the two conformations. The stem of SL3 is highlighted in blue, while orange and red highlights denote sequences that have complementary partner segments in the DRTE, which is shown in panel B. (B) SHAPE-guided fold of DRTE in PEMV1. Nucleotide reactivities are colour-coded and segments complementary to red and orange RNA segments in the PRTE are indicated. (C) SL2 and SL3 PRTE equivalents predicted in citrus vein enation virus (CVEV, NC_021564), with corresponding orange, red, and blue segments highlighted.