Table 2 Some mechanisms used by bacterial antisense RNAs [16]
Antisense/target | Organism | Mechanism | Description | Needs Hfq |
|---|---|---|---|---|
MicA/ompA | Escherichia coli | Direct (TIR) inhibition of translation | Trans-encoded; entails RNase E-dependent mRNA decay | Yes |
SgrS/ptsG | E. coli | Direct (TIR) inhibition of translation | Trans-encoded; SgrS also encoded o protein | Yes |
CopA/CopT | E. coli R1-type plasmids | Inhibition of translation | Cis-encoded; involves translational coupling | No |
IstR1/tisB | E. coli | Inhibition of translation | Trans-encoded; binding upstream of TIR inhibits standby ribosomes | No |
RNAIII/sa1000 | Staphylococcus aureus | Inhibition of translational initiation and induced RNase III cleavage | Trans-encoded; full inhibition requires both translation block and endocleavage; also contain open reading frame | No |
DsrA/rpoS | E. coli | Activation of RpoS translation | Trans-encoded; binding upstream of TIR | Yes |
RNAIII/repR | Streptococci plasmid plP501 | Riboswitch-like induction of premature transcription termination | Cis-encoded | ? |
GadY/gadXY | E. coli | Induced cleavage, stabilization of gadX mRNA | Cis-encoded between gadX and gadY | Yes |
OOP/cll | E. coli Lambda phage | Induced RNase III-mediated cleavage near 3’ end | Cis-encoded; causes subsequent cll mRNA decay | ? |
MicC/ompD | Salmonella | Direct targeting for mRNA decay | CDS-internal target; no effect on translational initiation | Yes |
RNAI/RNAII | E. coli ColE1-type plasmids | Inhibition of replication primer maturation | Cis-encoded; induces RNA folding change | No |
crRNAs/phage RNA/DNA? | Bacteria and archea | Mechanism is homology-dependent but unknown | CrRNAs processed from precursor RNA; anti-phage immunity | ? |