Table 1.
RNA Degradation Components Found in the Three Kingdoms of Life
|
Enzyme |
Activity |
Distributiona |
|---|---|---|
| Prokaryotic | ||
| RNAse E (rne) | Endoribonuclease; cuts single-stranded DNA adjacent to structured regions; provides internal access points for degradosome components | Eubacteria, Archaea (Eukarya—weak, exosome) |
| RNAse G (rng) | Endoribonuclease; cuts single-stranded DNA adjacent to structured regions; provides internal access points for degradosome components | Eubacteria, Archaea (weak) (Eukarya, weak) |
| RNAse III (rnc) | Endoribonuclease; cuts double-stranded DNA; provides internal access points for degradosome components | Eubacteria, Archaea some homologs in Eukarya |
| RNAse II (rnb) | 3′-5′ Exoribonuclease | Eubacteria |
| Polynucleotide | 3′-5′ Exoribonuclease | Eubacteria, Archaea some homologs in Eukarya |
| Phosphorylase (pnp) | ||
| Oligoribonuclease (orn) | 3′-5′ Exoribonuclease | Eubacteria, Archaea |
| Eukaryotic | ||
| Deadenylase (CCR4) | Removes nucleotides from 3′ polyA during translation (Chen et al. 2002; Tucker et al. 2002) | Eukarya |
| Decapping enzyme (DCP2) | Removes 5′ cap from deaenylated mRNA | Eukarya |
| Exonuclease (XRN1) | 5′-3′ exonuclease | Eukarya |
| Exosome (multiple)
|
3′-5′ exonuclease
|
Eukarya (prokaryotes, weak)
|
