mRNA interferase toxin, antitoxin is MazE; Toxic component of a type II toxin-antitoxin (TA) system. A sequence-specific endoribonuclease it inhibits protein synthesis by cleaving mRNA and inducing bacterial stasis. It is stable, single- strand specific with mRNA cleavage independent of the ribosome, although translation enhances cleavage for some mRNAs. Cleavage occurs at the 5'-end of ACA sequences, yielding a 2',3'-cyclic phosphate and a free 5'-OH, although cleavage can also occur on the 3'-end of the first A. Digests 16S rRNA in vivo 43 nts upstream of the C- terminus; this remove [...]

mRNA interferase toxin of toxin-antitoxin pair YafQ/DinJ; Toxic component of a type II toxin-antitoxin (TA) system. A sequence-specific mRNA endoribonuclease that inhibits translation elongation and induces bacterial stasis. Cleavage occurs between the second and third residue of the Lys codon followed by a G or A (5'AAA(G/A)3'), is reading-frame dependent and occurs within the 5' end of most mRNAs. Ribosome-binding confers the sequence specificity and reading frame- dependence. When overexpressed in liquid media YafQ partially inhibits protein synthesis, with a reduction in growth rat [...]

Qin prophage; Toxic component of a type II toxin-antitoxin (TA) system. A sequence-specific, ribosome-dependent mRNA endoribonuclease that inhibits translation during amino acid starvation (the stringent response). In vitro acts by cleaving mRNA with high codon specificity in the ribosomal A site between positions 2 and 3. The stop codon UAG is cleaved at a fast rate while UAA and UGA are cleaved with intermediate and slow rates. In vitro mRNA cleavage can also occur in the ribosomal E site after peptide release from peptidyl- tRNA in the P site as well as on free 30S subunits. In vivo [...]

Toxin of the YoeB-YefM toxin-antitoxin system; Toxic component of a type II toxin-antitoxin (TA) system. Its mode of function is controversial; it has been proposed to be an mRNA interferase but also an inhibitor of translation initiation. When overproduced in wild-type cells, inhibits bacterial growth and translation by cleavage of mRNA molecules while it has a weak effect on colony forming ability. Overproduction of Lon protease specifically activates YoeB-dependent mRNA cleavage, leading to lethality. YefM binds to the promoter region of the yefM-yeoB operon to repress transcription [...]

Antitoxin of the YoeB-YefM toxin-antitoxin system; Antitoxin component of a type II toxin-antitoxin (TA) system. Antitoxin that counteracts the effect of the YoeB toxin. YefM binds to the promoter region of the yefM-yeoB operon to repress transcription, YeoB acts as a corepressor.

GCU-specific mRNA interferase toxin of the MqsR-MqsA toxin-antitoxin system; Toxic component of a type II toxin-antitoxin (TA) system. Plays a significant role in the control of biofilm formation and induction of persister cells in the presence of antibiotics. An mRNA interferase which has been reported to be translation-independent. It has also been reported to be translation-dependent. Cleavage has been reported to occur on either side of G in the sequence GCU. Also reported to cleave after C in GC(A/U) sequences. There are only 14 genes in E.coli W3110 (and probably also MG1655) tha [...]

mRNA interferase toxin of the HicAB toxin-antitoxin system; Toxic component of a type II toxin-antitoxin (TA) system. A probable translation-independent mRNA interferase. Overexpression causes cessation of cell growth and inhibits cell proliferation via inhibition of translation; this blockage is overcome (after 90 minutes) by subsequent expression of antitoxin HicB. Overexpression causes cleavage of a number of mRNAs and tmRNA, in a translation-independent fashion, suggesting this is an mRNA interferase. mRNA interferases play a role in bacterial persistence to antibiotics ; Belongs t [...]

Antitoxin for the HicAB toxin-antitoxin system; Antitoxin component of a type II toxin-antitoxin (TA) system. Functions as an mRNA interferase antitoxin; overexpression prevents HicA-mediated cessation of cell growth and inhibition of cell proliferation.

Antitoxin of the RelE-RelB toxin-antitoxin syste; Antitoxin component of a type II toxin-antitoxin (TA) system. Counteracts the effect of cognate toxin RelE via direct protein-protein interaction, preventing RelE from entering the ribosome A site and thus inhibiting its endoribonuclease activity. An autorepressor of relBE operon transcription. 2 RelB dimers bind to 2 operator sequences; DNA- binding and repression is stronger when complexed with toxin/corepressor RelE by conditional cooperativity. Increased transcription rate of relBE and activation of relE is consistent with a lower l [...]