Fig. 9: P4 and P5 form a continuous helix and stabilize pk-1 through an A-minor motif.
From: Scaffold-enabled high-resolution cryo-EM structure determination of RNA
A The structural organization of the P4 and P5 helices is shown relative to pk-1. The minor grooves of P5 and pk-1 point towards each other and form an extended interface of hydrogen bonds. B The base of P5 consists of several noncanonical base pairs that forms a continuous helix between P4 and P5, and extrudes A57 and A58 from the helical axis. C A57 and A58 from the base of P5 extend into the minor groove of pk-1 forming an extended A-minor motif interaction.
