Table 1.

Characteristic features of the functionally characterized bacterial antisense RNAs discussed in the texta

asRNAHostPhylumLength(s)Functional mechanism(s) of asRNA actionOutcomeReference(s)
AmgRSalmonella entericaGammaproteobacteria1.2 kbCodegradation; complementary to mgtC of the mgtCBR operon; likely RNase E dependentDynamic adjustment of MgtC and MgtB protein levels48
GadYEscherichia coliGammaproteobacteria105 nt, 90 nt, 59 ntCleavage of the bicistronic gadXW mRNA, likely by RNases III and E and other unknown factorsEnhanced stability of gadX mRNA65, 66, 90, 97
SibABCDEEscherichia coliGammaproteobacteria∼140 ntInterference with translation and/or stability of mRNA suggestedRepression of IbsABCDE toxin synthesis25
IsrRSynechocystis PCC6803Cyanobacteria177 ntCodegradation with isiA mRNAThreshold linear response; delayed induction of isiA under stress and faster recovery21, 50
mccA asRNAClostridium acetobutylicumFirmicutes1,000 nt, 700 nt, 400 nt, 200 ntTranscriptional interference with the convergent ubiG-mccBA promoterSulfur-dependent control of the ubiG-mccBA operon3
OOP asRNABacteriophage λSiphoviridae77 ntCodegradation; RNase III-dependent cleavage of the mRNA cIIRepression of cII; involved in lysis-lysogeny decision; favors lysis4446, 106
CfrICyanomyovirus S-PM2Myoviridae225 ntUnknownUnknown59
Ribosomal protein operon/genomic island asRNAsProchlorococcus MED4Cyanobacteria3,500 nt, 7,000 ntMasking of RNase E sitesEnhanced half-life upon phage infection86
RNAαVibrio anguillarumGammaproteobacteria650 ntComplementary to the fatB gene of the iron transport-biosynthesis operonRepression of fatA and fatB under iron-rich conditions12, 73, 95, 103, 104
RNAβVibrio anguillarumGammaproteobacteria427 ntComplementary to the 3′ region of fatA and the 5′ end of angRTermination of transcription12, 73, 89
RnaGShigella flexneriGammaproteobacteria450 ntComplementary to the 5′ UTR of the icsA (virG) virulence gene; transcriptional interference with the convergent icsA promoter and transcription attenuation of icsA mRNAPremature termination of transcription and direct reduction of icsA transcription28
SymREscherichia coliGammaproteobacteria77 ntOverlaps the symE mRNA 5′ end and RBS, preventing the initiation of translationControl of SymE translation40
ureAB asRNAsHelicobacter pyloriEpsilonproteobacteria290 ntProcessing or terminationpH-dependent regulation of ureAB105
  • a RBS, ribosome binding site.