Fig. 1: Structural organization of Zika xrRNA.

a Ribbon representation of the 71-nucleotide long xrRNA of the Zika virus, PDB entry 5TPY³. b Diagrammatic representation of canonical and noncanonical base pairings, as annotated by Barnaba⁴⁷. c Heat map of the native contacts. The map includes heavy-atom interactions within a 4 Å cutoff distance and thus include contacts formed by bases, sugar, and phosphate moieties. The four helices, P1–P4, and pseudoknotted regions, Pk1–Pk5, are highlighted. Diagram in b follows ref. ³. Secondary elements are highlighted with the same color code across the three panels. Structural renderings are based on the VMD software package⁴⁸.