Alternate ribosome-rescue factor A; Rescues ribosomes stalled at the 3' end of non-stop mRNAs. This activity is crucial when the stalled ribosome cannot be rescued by the SsrA(tmRNA)-SmpB quality control system. Binds the 30S subunit, contacting 16S rRNA with the N-terminus near the decoding center and its C-terminus in the mRNA entry channel; contacts change in the presence of release factor 2 (RF2, also named PrfB). Requires RF2/PrfB to hydrolyze stalled peptidyl-tRNA on the ribosome; recruits and probably helps position RF2/PrfB correctly in the ribosomal A site so RF2's GGQ motif c [...]

Alternative stalled-ribosome rescue factor B; Rescues stalled ribosomes. Can hydrolyze peptidyl-tRNA on ribosomes stalled by both non-stop mRNAs and mRNAs that contain rare codon clusters or ribosomes stalled in the middle of mRNA. First identified as a complementary ribosome rescue system when the stalled ribosome cannot be rescued by the SsrA(tmRNA)- SmpB quality control system or the alternative ribosome-rescue factor A (arfA).

Alternate ribosome-rescue factor A; Rescues ribosomes stalled at the 3' end of non-stop mRNAs. This activity is crucial when the stalled ribosome cannot be rescued by the SsrA(tmRNA)-SmpB quality control system. Binds the 30S subunit, contacting 16S rRNA with the N-terminus near the decoding center and its C-terminus in the mRNA entry channel; contacts change in the presence of release factor 2 (RF2, also named PrfB). Requires RF2/PrfB to hydrolyze stalled peptidyl-tRNA on the ribosome; recruits and probably helps position RF2/PrfB correctly in the ribosomal A site so RF2's GGQ motif c [...]

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 [...]

Alternate ribosome-rescue factor A; Rescues ribosomes stalled at the 3' end of non-stop mRNAs. This activity is crucial when the stalled ribosome cannot be rescued by the SsrA(tmRNA)-SmpB quality control system. Binds the 30S subunit, contacting 16S rRNA with the N-terminus near the decoding center and its C-terminus in the mRNA entry channel; contacts change in the presence of release factor 2 (RF2, also named PrfB). Requires RF2/PrfB to hydrolyze stalled peptidyl-tRNA on the ribosome; recruits and probably helps position RF2/PrfB correctly in the ribosomal A site so RF2's GGQ motif c [...]

tmRNA-binding trans-translation protein; Required for rescue of stalled ribosomes mediated by trans- translation. Binds to tmRNA RNA (also known as SsrA or 10Sa RNA, 363 nucleotides in this organism), required for stable binding of tmRNA to ribosomes. tmRNA and SmpB together mimic tRNA shape, replacing the anticodon stem-loop with SmpB (Probable). tmRNA is encoded by the ssrA gene; the 2 termini fold to resemble tRNA(Ala) and it encodes a 'tag peptide', a short internal open reading frame. Able to recruit charged tmRNA to ribosomes. Does not play a role in transcription, processing or [...]

Alternative stalled-ribosome rescue factor B; Rescues stalled ribosomes. Can hydrolyze peptidyl-tRNA on ribosomes stalled by both non-stop mRNAs and mRNAs that contain rare codon clusters or ribosomes stalled in the middle of mRNA. First identified as a complementary ribosome rescue system when the stalled ribosome cannot be rescued by the SsrA(tmRNA)- SmpB quality control system or the alternative ribosome-rescue factor A (arfA).

Alternate ribosome-rescue factor A; Rescues ribosomes stalled at the 3' end of non-stop mRNAs. This activity is crucial when the stalled ribosome cannot be rescued by the SsrA(tmRNA)-SmpB quality control system. Binds the 30S subunit, contacting 16S rRNA with the N-terminus near the decoding center and its C-terminus in the mRNA entry channel; contacts change in the presence of release factor 2 (RF2, also named PrfB). Requires RF2/PrfB to hydrolyze stalled peptidyl-tRNA on the ribosome; recruits and probably helps position RF2/PrfB correctly in the ribosomal A site so RF2's GGQ motif c [...]

Alternative stalled-ribosome rescue factor B; Rescues stalled ribosomes. Can hydrolyze peptidyl-tRNA on ribosomes stalled by both non-stop mRNAs and mRNAs that contain rare codon clusters or ribosomes stalled in the middle of mRNA. First identified as a complementary ribosome rescue system when the stalled ribosome cannot be rescued by the SsrA(tmRNA)- SmpB quality control system or the alternative ribosome-rescue factor A (arfA).

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 [...]

Alternative stalled-ribosome rescue factor B; Rescues stalled ribosomes. Can hydrolyze peptidyl-tRNA on ribosomes stalled by both non-stop mRNAs and mRNAs that contain rare codon clusters or ribosomes stalled in the middle of mRNA. First identified as a complementary ribosome rescue system when the stalled ribosome cannot be rescued by the SsrA(tmRNA)- SmpB quality control system or the alternative ribosome-rescue factor A (arfA).

tmRNA-binding trans-translation protein; Required for rescue of stalled ribosomes mediated by trans- translation. Binds to tmRNA RNA (also known as SsrA or 10Sa RNA, 363 nucleotides in this organism), required for stable binding of tmRNA to ribosomes. tmRNA and SmpB together mimic tRNA shape, replacing the anticodon stem-loop with SmpB (Probable). tmRNA is encoded by the ssrA gene; the 2 termini fold to resemble tRNA(Ala) and it encodes a 'tag peptide', a short internal open reading frame. Able to recruit charged tmRNA to ribosomes. Does not play a role in transcription, processing or [...]

Antitoxin of YafQ-DinJ toxin-antitoxin system; Antitoxin component of a type II toxin-antitoxin (TA) system. A labile antitoxin that counteracts the effect of cognate toxin YafQ. YafQ and DinJ together bind their own promoter, and repress its expression. There are 2 operators with imperfect inverted repeats (IR) in the dinJ promoter, YafQ-(DinJ)2-YafQ only binds to the first (most upstream) of them to repress transcription; binding to a single IR is sufficient for activity in vivo and in vitro. DinJ alone is as potent a transcriptional repressor as the heterotetramer and also only need [...]

mRNA interferase toxin of the HigB-HigA toxin-antitoxin system; Toxic component of a type II toxin-antitoxin (TA) system. A probable translation-dependent mRNA interferase. Overexpression causes cessation of cell growth and inhibits cell proliferation via inhibition of translation; this blockage is overcome by subsequent expression of antitoxin HigA. Overexpression causes cleavage of a number of mRNAs in a translation-dependent fashion, suggesting this is an mRNA interferase. mRNA interferases play a role in bacterial persistence to antibiotics; overexpression of this protein induces p [...]

Antitoxin of YafQ-DinJ toxin-antitoxin system; Antitoxin component of a type II toxin-antitoxin (TA) system. A labile antitoxin that counteracts the effect of cognate toxin YafQ. YafQ and DinJ together bind their own promoter, and repress its expression. There are 2 operators with imperfect inverted repeats (IR) in the dinJ promoter, YafQ-(DinJ)2-YafQ only binds to the first (most upstream) of them to repress transcription; binding to a single IR is sufficient for activity in vivo and in vitro. DinJ alone is as potent a transcriptional repressor as the heterotetramer and also only need [...]

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 [...]

Antitoxin of YafQ-DinJ toxin-antitoxin system; Antitoxin component of a type II toxin-antitoxin (TA) system. A labile antitoxin that counteracts the effect of cognate toxin YafQ. YafQ and DinJ together bind their own promoter, and repress its expression. There are 2 operators with imperfect inverted repeats (IR) in the dinJ promoter, YafQ-(DinJ)2-YafQ only binds to the first (most upstream) of them to repress transcription; binding to a single IR is sufficient for activity in vivo and in vitro. DinJ alone is as potent a transcriptional repressor as the heterotetramer and also only need [...]

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 [...]

Antitoxin of YafQ-DinJ toxin-antitoxin system; Antitoxin component of a type II toxin-antitoxin (TA) system. A labile antitoxin that counteracts the effect of cognate toxin YafQ. YafQ and DinJ together bind their own promoter, and repress its expression. There are 2 operators with imperfect inverted repeats (IR) in the dinJ promoter, YafQ-(DinJ)2-YafQ only binds to the first (most upstream) of them to repress transcription; binding to a single IR is sufficient for activity in vivo and in vitro. DinJ alone is as potent a transcriptional repressor as the heterotetramer and also only need [...]

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 [...]

Antitoxin of YafQ-DinJ toxin-antitoxin system; Antitoxin component of a type II toxin-antitoxin (TA) system. A labile antitoxin that counteracts the effect of cognate toxin YafQ. YafQ and DinJ together bind their own promoter, and repress its expression. There are 2 operators with imperfect inverted repeats (IR) in the dinJ promoter, YafQ-(DinJ)2-YafQ only binds to the first (most upstream) of them to repress transcription; binding to a single IR is sufficient for activity in vivo and in vitro. DinJ alone is as potent a transcriptional repressor as the heterotetramer and also only need [...]

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.

Antitoxin of YafQ-DinJ toxin-antitoxin system; Antitoxin component of a type II toxin-antitoxin (TA) system. A labile antitoxin that counteracts the effect of cognate toxin YafQ. YafQ and DinJ together bind their own promoter, and repress its expression. There are 2 operators with imperfect inverted repeats (IR) in the dinJ promoter, YafQ-(DinJ)2-YafQ only binds to the first (most upstream) of them to repress transcription; binding to a single IR is sufficient for activity in vivo and in vitro. DinJ alone is as potent a transcriptional repressor as the heterotetramer and also only need [...]

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 [...]

mRNA interferase toxin of the HigB-HigA toxin-antitoxin system; Toxic component of a type II toxin-antitoxin (TA) system. A probable translation-dependent mRNA interferase. Overexpression causes cessation of cell growth and inhibits cell proliferation via inhibition of translation; this blockage is overcome by subsequent expression of antitoxin HigA. Overexpression causes cleavage of a number of mRNAs in a translation-dependent fashion, suggesting this is an mRNA interferase. mRNA interferases play a role in bacterial persistence to antibiotics; overexpression of this protein induces p [...]

Antitoxin of YafQ-DinJ toxin-antitoxin system; Antitoxin component of a type II toxin-antitoxin (TA) system. A labile antitoxin that counteracts the effect of cognate toxin YafQ. YafQ and DinJ together bind their own promoter, and repress its expression. There are 2 operators with imperfect inverted repeats (IR) in the dinJ promoter, YafQ-(DinJ)2-YafQ only binds to the first (most upstream) of them to repress transcription; binding to a single IR is sufficient for activity in vivo and in vitro. DinJ alone is as potent a transcriptional repressor as the heterotetramer and also only need [...]

mRNA interferase toxin of the HigB-HigA toxin-antitoxin system; Toxic component of a type II toxin-antitoxin (TA) system. A probable translation-dependent mRNA interferase. Overexpression causes cessation of cell growth and inhibits cell proliferation via inhibition of translation; this blockage is overcome by subsequent expression of antitoxin HigA. Overexpression causes cleavage of a number of mRNAs in a translation-dependent fashion, suggesting this is an mRNA interferase. mRNA interferases play a role in bacterial persistence to antibiotics; overexpression of this protein induces p [...]

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 the HigB-HigA toxin-antitoxin system; Toxic component of a type II toxin-antitoxin (TA) system. A probable translation-dependent mRNA interferase. Overexpression causes cessation of cell growth and inhibits cell proliferation via inhibition of translation; this blockage is overcome by subsequent expression of antitoxin HigA. Overexpression causes cleavage of a number of mRNAs in a translation-dependent fashion, suggesting this is an mRNA interferase. mRNA interferases play a role in bacterial persistence to antibiotics; overexpression of this protein induces p [...]

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 [...]

mRNA interferase toxin of the HigB-HigA toxin-antitoxin system; Toxic component of a type II toxin-antitoxin (TA) system. A probable translation-dependent mRNA interferase. Overexpression causes cessation of cell growth and inhibits cell proliferation via inhibition of translation; this blockage is overcome by subsequent expression of antitoxin HigA. Overexpression causes cleavage of a number of mRNAs in a translation-dependent fashion, suggesting this is an mRNA interferase. mRNA interferases play a role in bacterial persistence to antibiotics; overexpression of this protein induces p [...]

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 [...]

mRNA interferase toxin of the HigB-HigA toxin-antitoxin system; Toxic component of a type II toxin-antitoxin (TA) system. A probable translation-dependent mRNA interferase. Overexpression causes cessation of cell growth and inhibits cell proliferation via inhibition of translation; this blockage is overcome by subsequent expression of antitoxin HigA. Overexpression causes cleavage of a number of mRNAs in a translation-dependent fashion, suggesting this is an mRNA interferase. mRNA interferases play a role in bacterial persistence to antibiotics; overexpression of this protein induces p [...]

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.

mRNA interferase toxin of the HigB-HigA toxin-antitoxin system; Toxic component of a type II toxin-antitoxin (TA) system. A probable translation-dependent mRNA interferase. Overexpression causes cessation of cell growth and inhibits cell proliferation via inhibition of translation; this blockage is overcome by subsequent expression of antitoxin HigA. Overexpression causes cleavage of a number of mRNAs in a translation-dependent fashion, suggesting this is an mRNA interferase. mRNA interferases play a role in bacterial persistence to antibiotics; overexpression of this protein induces p [...]

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 [...]

Specificity determinant for hsdM and hsdR; The M and S subunits together form a methyltransferase (MTase) that methylates two adenine residues in complementary strands of a bipartite DNA recognition sequence. In the presence of the R subunit the complex can also act as an endonuclease, binding to the same target sequence but cutting the DNA some distance from this site. Whether the DNA is cut or modified depends on the methylation state of the target sequence. When the target site is unmodified, the DNA is cut. When the target site is hemimethylated, the complex acts as a maintenance M [...]

DLP12 prophage; Protease that can cleave T7 RNA polymerase, ferric enterobactin receptor protein (FEP), antimicrobial peptide protamine and other proteins. This protease has a specificity for paired basic residues.

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 [...]

Antitoxin of YafQ-DinJ toxin-antitoxin system; Antitoxin component of a type II toxin-antitoxin (TA) system. A labile antitoxin that counteracts the effect of cognate toxin YafQ. YafQ and DinJ together bind their own promoter, and repress its expression. There are 2 operators with imperfect inverted repeats (IR) in the dinJ promoter, YafQ-(DinJ)2-YafQ only binds to the first (most upstream) of them to repress transcription; binding to a single IR is sufficient for activity in vivo and in vitro. DinJ alone is as potent a transcriptional repressor as the heterotetramer and also only need [...]