. 2003 Jul 1;31(13):3432–3440. doi: 10.1093/nar/gkg539

Table 1. Classification of 236 pseudoknots in PseudoBase. Pseudoknots marked with * contain more than one basic type.

Type	Pseudoknots	No. of occurrences	Ratio of occurrences (%)
H	All others	180	76.3
LL	RSV, CGMMV_PKbulge, ORSV-S1-PKbulge1∼3, PMMV-S_PKbulge, STMV_PKbulge, TMGMV_PKbulge, TMV_PKbulge, TMV-L_Pkbulge, Ec_RNaseP-P6, HDV-It_ag	12	5.1
HL_OUT	AMV3, BBMV3, BMV3, BSMVbeta, CCMV3, CMV3, LRSVbeta, PSLVbeta, satRPV, BVDV_IRES, CSFV_IRES, BQCV_IRES-PKIII, CrPV_IRES-PKIII, DCV_IRES-PKIII, HiPV_IRES-PKIII, HDV-It_ag*, PSIV_IRES-PKIII, RhPV_IRES-PKIII, TrV_IRES-PKIII, Ec_23S-PKG12, Ec_RNaseP-P4, NGF-H1, NGF-L2, NGF-L6	24	10.2
HL_IN	BBMV3, BMV3, BSMVbeta, CCMV3, CMV3, LRSVbeta, Vp_PK2, PSLVbeta*, Pp_18S-PKE23-9/12, Ec_16S-PK570/866, Bp_PK2	11	4.7
HH	HCV_IRES	1	0.4
HHH	HCV_229E, CoxB3, Ni_VS, satRPV, Ec_RNaseP-P6, Hs_SRP-pkn	6	2.5
Unclassified	Ec_alpha, HDV-It_g	2	0.8
Total		236	100.0