Table 4.
Predicted functions of common cas-genes in archaea. Data are summarized from Makarova et al. 2006 and earlier papers (Jansen et al. 2002, Makarova et al. 2002, Haft et al. 2005). Symbols: * = formerly COG3578; and ** = formerly COG3574.
| Family/cas-name | Predicted function | Comments |
| COG1518/cas1 | Nuclease/integrase | Possibly involved in inserting new DNA sequences |
| COG1343/cas2 | Nuclease | Possibly involved in inserting new DNA sequences |
| COG1203/cas3 | DNA helicase | Often fused to HD-nuclease domain/ related to COG2254 |
| COG2254 | HD-like nuclease | |
| COG1468/cas4 | RecB-like nuclease | |
| COG1688/cas5 | RNA-binding | “Ramp” superfamily |
| COG1583/cas6 | RNA-binding | “Ramp” superfamily |
| COG4343*/csa1 | RecB-like nuclease | |
| COG1857/csa2 | Nuclease | |
| COG2462/csa3 | HTH-type transcriptional regulator | |
| COG1353 | RNA polymerase | “Loosely” associated with repeat clusters |
| AF0070/csa4 | None | Crenarchaea-specific |
| AF1870**/csa5 | None | Crenarchaea-specific |