Table 1.

Class membership of 212 pseudoknots from PseudoBase. The sequences were determined by comparative sequence analysis and/or by experimental techniques. The largest class of pseudoknots is simple recursive or even canonical simple recursive.

simple recursive pseudoknots
csr-PK	1-nt bulge	Rule 2 violated	isolated basepair	G-A basepair	total
135	11	6	17	3	172
complex pseudoknots
internal loop	triple helix	four helices	kissing hairpins	large bulge	total
23	12	1	3	1	40