Predicted secondary structure of the 16S rRNA gene of R. similis. Watson-Crick base pairing and G:U base pairing is indicated by a line and a dot, respectively. Numbering of helices is according to De Rijk et al.  and other published nematode mt rRNA structures. Binding sites for the amino-acyl of tRNAs (A), peptidyl-transferase (P), or both (AP) as defined by Noller  and Hu  are indicated. Compared to other nematode 16S rRNAs, shaded nucleotides are conserved in at least 90% of the cases, while arrows indicate remarkable deletions.