Table 1. RNA pol common subunit composition.
| Eukaryotes |
|||||
| Bacteria | Archaea | RNA pol I, II, III | RNA pol IV (plants) | RNA pol V (plants) | RNA pol trypanosome |
| - | Rpo5 (RpoH) | RPB5 | [3] | NRPES5 | RPB5/RPB5z |
| ω | Rpo6 (RpoK) | RPB6 | [1] | RPB6/RPB6z | |
| - | RpoG* | RPB8 | [1] | [1] | |
| - | Rpo10 (RpoN) | RPB10 | |||
| - | Rp012 (RpoP) | RPB12 | |||
For plants and trypanosome, subunits are indicated only when they change; the numbers in square brackets indicate the number of orthologues of RNA pol IV and RNA pol V subunits in plants with respect to these of RNA pol I, II and III. *Subunits RpoG have been identified only in some archaeal species [12]. Different names for common subunits of yeast RNA pol: Rpb5: ABC27; Rpb6: ABC23 or Rpo26; Rpb8: ABC14.5; Rpb10: ABC10β; Rpb12: ABC10α.