Secondary structure of L. macaronius rrnS. Each helix is numbered progressively from the 5' to the 3' end together with the first nucleotide belonging to the helix itself. Domains are labeled with Roman numerals. Tertiary structures are denoted by boxed bases joined by solid lines. Watson-Crick pairs are joined by dashes. GT pairs are joined by a blue dot, while other non-canonical pairs are connected by a red dot.