“HIGH-Motif 2” codon assignment and base pairing.

First and last row are consensus residues according to the structure-based MSA, “+” indicates gaps. Signature regions according to [8] are emphasized. Sequence numbers are given according to the MSA. Middle rows indicate consensus codons; unassigned positions are indicated by dots, matches by vertical lines, and mismatches by “x”. Arginine Tweezers and Backbone Brackets residues are framed by boxes.