Table 3. Overall statistics of topologically classified primitive pseudoknots.
| Genus | Subclass | Pseudoknot pattern | No. of RNA sequences with this primitive pseudoknot | Avg. length±std.dev. (nts) | Min. length (nts) |
| 1 | 1A | ABAB | 1688 | 204.6±294.9 | 17 |
| 1 | 1B | ABACBC | 365 | 253.6±282.5 | 40 |
| 1 | 1C | ABCABC | 51 | 73.6±43.9 | 37 |
| 2 | 2A | ABCACDBD | 45 | 53.3±0.5 | 53 |
| 2 | 2B | ABCDCADB | 5 | 71.4±1.2 | 69 |
| 2 | 2C | ABCDEDBCAE | 2 | 347.5±5.5 | 342 |
| 2 | 2D | ABCBDEDCAFEF | 1 | 1452±0 | 1452 |
| 3 | 3A | ABACDEFGEHGIJIFHKBKDJC | 48 | 2637.4±181.2 | 2268 |
| 3 | 3B | ABCDEFDGFHIHEGJAJCIB | 5 | 2742.8±408.4 | 2294 |
| 3 | 3C | ABACDEDFGFECHBHIGI | 5 | 2652.6±12.7 | 2643 |
| 3 | 3D | ABACDEFDGFHIHEGJBJIC | 1 | 2548±0 | 2548 |
| 4 | 4A | ABCDEFEGCGHIAIJKBKFJHD | 1 | 369±0 | 369 |
| 4 | 4B | ABACDEFGHEGIHJKJFILBLDKC | 1 | 2617±0 | 2617 |
| 5 | 5A | ABCDEFEGHCHIJIGKALJLMNBNFMKD | 2 | 431±0 | 431 |
The length is measured as the end-to-end distance between (and including) the leftmost base paired nucleotide and the rightmost base paired nucleotide.