Figure 9

The full library of topologies for dual graphs between 2 and 4 vertices. The current status of existing, RNA-like, and non-RNA-like topologies is represented by red, blue or black (dashed) colors, respectively, based on the new clustering approach. The structural class (tree, bridge or pseudoknot) is also shown for each graph. Ten candidate topologies (C1-C10) in 2004 suggested by PAM are shown in the yellow box. See the RAG website for the library of topologies with 5-9 vertices.