Identification of Hammerhead Ribozymes in All Domains of Life Reveals Novel Structural Variations
Figure 2
Type II hammerhead and representative pseudoknot substructures in type I, II and III ribozymes from diverse sources.
(A) Consensus sequence and secondary structure of widespread type II hammerhead ribozymes identified in this study. A pseudoknot forms the tertiary contacts that are presumed to stabilize parallel orientation of stems I and II. (B) Sequences and secondary structures of four type II hammerhead ribozymes. Diagrams reflect the orientation of stems I and II in the catalytically active structure. Closed circles represent wobble base pairs and the open square and triangle represent a trans Hoogsteen/sugar-edge interaction [65]. Arrowhead indicates cleavage site.