Fig. 2: Comparison of the secondary structures of J-K-St.

a The secondary structure of J-K-St in the complex with eIF4GHEAT1 and eIF4A, determined by cryo-EM in this study. Bases that are not modeled are shown in light gray. b The secondary structure of the J-K-St in the free state, determined by NMR9. Lines between bases indicate the canonical Watson–Crick base pairs, dots indicate the wobble base pairs, and dashed lines are for non-canonical base pairs. The eIF4GHEAT1-binding residues are highlighted with purple lines. The J, K, St, and ASL domains are colored green, blue, orange, and red, respectively. The differences between these two structures are highlighted by gray backgrounds.