ライフサイエンスコーパス: tmRNA

1 tmRNA and SmpB have been found in all bacteria and are e

2 tmRNA combines tRNA and mRNA properties and helps bacter

3 tmRNA contains a transfer RNA (tRNA)-like domain (TLD),

4 tmRNA is a small regulatory RNA that is ubiquitous in ba

5 tmRNA is a versatile and highly conserved bacterial mole

6 tmRNA is strongly attached to the 30S subunit head by mu

7 tmRNA rescues stalled ribosomes in eubacteria by forcing

8 tmRNA, encoded by the ssrA gene, is a bifunctional molec

9 tmRNA-SmpB interacts with translational complexes stalle

10 ibosome recycling factor do not constitute a tmRNA-independent rescue pathway, as previously suggeste

11 e capable of rescuing stalled ribosomes in a tmRNA-independent manner.

12 Here, we present the crystal structure of a tmRNA fragment, SmpB and elongation factor Tu bound to t

13 SmpB, a tmRNA-binding protein, protects SsrA RNA from RNase R de

14 bility using an unrelated sequence yielded a tmRNA mutant with nearly wild-type activity.

15 pB protein that restore the function of A86C tmRNA in vivo.

16 he plastid, where mature SmpB could activate tmRNA.

17 Additionally, tmRNA.SmpB-mediated SsrA peptide tagging was significant

18 A complex of alanyl-tmRNA (which functions as a tRNA and mRNA), SmpB protein

19 ial sRNAs (6S, RNaseP_bact_a, ffs, and alpha-tmRNA) was next confirmed by Northern hybridization.

20 ficantly lower levels of A-site cleavage and tmRNA.SmpB activity.

21 d function modulate A-site mRNA cleavage and tmRNA.SmpB activity.

22 actor 3 did not have comparable effects, and tmRNA was incapable of attacking TnaC-tRNA(2)(Pro) in st

23 bacteria are also regulated by RNase III and tmRNA.

24 Fs encoding a putative signaling peptide and tmRNA in T. maritima is intriguing, since this overlappi

25 ependent on the presence of SmpB protein and tmRNA, suggesting a requirement for active transtranslat

26 endent on the activities of SmpB protein and tmRNA.

27 The original mRNA is released and tmRNA becomes the template for translation of a 10-amino

28 P RNA, signal-recognition particle RNA, and tmRNA is facilitated by their cognate polymerase pausing

29 To probe interactions between S1 and tmRNA, truncated variants missing one or more of the six

30 However, the binding of SmpB and tmRNA does not alter RNase R activity.

31 nditions roughly similar numbers of SmpB and tmRNA molecules are present in cells.

32 To elucidate the contributions of SmpB and tmRNA to RNase R recruitment, we evaluated Escherichia c

33 ignificance of conserved regions of SmpB and tmRNA to the trans-translation process.

34 trans-Translation, orchestrated by SmpB and tmRNA, is the principal eubacterial pathway for resolvin

35 examine 87 Escherichia coli MG1655 tRNA and tmRNA genes and their orthologues in E.coli EDL933, E.co

36 Our algorithm generates a list of tRNA and tmRNA genes, uses each as the query for a BLAST search o

37 contents and contexts of bacterial tRNA and tmRNA genes, which are known insertion hotspots for geno

38 riguing, since this overlapping arrangement (tmRNA associated with putative small ORFs) was found to

39 its protein partner, SmpB (small protein B), tmRNA enters stalled ribosomes and transfers an Ala resi

40 When protein synthesis stalls in bacteria, tmRNA acts first as a surrogate tRNA and then as an mRNA

41 The bacterial tmRNA.SmpB system facilitates recycling of stalled trans

42 The bacterial tmRNA.SmpB system recycles stalled translation complexes

43 lineages suggests that loop-opening benefits tmRNA function.

44 bosomes does not involve competition between tmRNA and other translation factors for A-sites that are

45 Interactions observed between tmRNA and RpsA WT, RpsA DeltaA438, and each of the trunc

46 domain (R1) plays a critical role in binding tmRNA and mRNA but requires additional N- or C-terminal

47 Ribosomal protein S1 binds tmRNA, but its functional role in tmRNA-mediated tagging

48 er from termination-paused ribosomes in both tmRNA(+) and DeltatmRNA cells, whereas other termination

49 stop mRNA, tmRNA levels did not increase but tmRNA-mediated tagging increased substantially.

50 stop codons was dramatically accelerated by tmRNA.SmpB.

51 Therefore, ArfA levels are controlled by tmRNA through ssrA-peptide tagging and proteolysis.

52 nce called the ssrA tag, which is encoded by tmRNA and allows normal termination and release of ribos

53 om truncated mRNA and therefore regulated by tmRNA tagging activity.

54 ective messenger RNAs (mRNAs) are rescued by tmRNA, an approximately 300-nucleotide-long molecule tha

55 d during protein synthesis can be rescued by tmRNA, which acts first as a tRNA and then as an mRNA to

56 ng, and the rescuing of stalled ribosomes by tmRNA.

57 s with RNase R in vitro and is stimulated by tmRNA.

58 over, +1 frameshifting was not suppressed by tmRNA.SmpB activity, suggesting that recoding and riboso

59 proteins were identified that are tagged by tmRNA under normal growth conditions.

60 In G(1)-phase cells, tmRNA was found in regularly spaced foci indicative of a

61 f IdeR and Zur regulated mRNAs and to cleave tmRNA in M. tuberculosis, Escherichia coli and Mycobacte

62 assays to study the role of Escherichia coli tmRNA in trans-translation.

63 Although not essential in Escherichia coli, tmRNA activity is essential for bacterial survival under

64 proposed secondary structure combines common tmRNA features differently from the structures of other

65 Lists of the tmRNAs and the corresponding tmRNA-encoded tag-peptides are presented in alphabetical

66 In Caulobacter crescentus, tmRNA was localized in a cell-cycle-dependent manner.

67 that the AAA+ Lon protease can also degrade tmRNA-tagged proteins, but with much lower efficiency.

68 RNase R, the nuclease that degrades tmRNA, was localized in a helix-like pattern that was se

69 ough A-site-cleaved mRNAs were not detected, tmRNA-mediated ssrA tagging after SecM glycine 165 was o

70 In many species, mutations that disrupt tmRNA activity cause defects in growth or development.

71 s of the pseudoknots and protein SmpB during tmRNA folding, maturation, and protein synthesis.

72 he emergence of mutant strains with elevated tmRNA transcription.

73 res with translation termination and elicits tmRNA.SmpB activity.

74 Some plastid genomes encode tmRNA, but smpB genes have only been reported from bacte

75 uitous in eubacteria, the ssrA gene encoding tmRNA is not essential for the viability of Escherichia

76 Protein SmpB enhanced tmRNA processing, suggesting a new role for SmpB in tran

77 o gain further insights, we used established tmRNA and SmpB variants that impact distinct stages of t

78 tion, we report the discovery of an extended tmRNA tag and extensive ladder-like pattern of endogenou

79 Pseudoknot 4 not only facilitated tmRNA maturation but also promoted tagging.

80 ely disrupts their interaction, facilitating tmRNA-SmpB binding.

81 s on the activity of ribosome rescue factors tmRNA and ArfA.

82 Diatom SmpB was active for tmRNA translation with bacterial components in vivo and

83 able to bind ribosomes, and its affinity for tmRNA was only slightly diminished.

84 ribosomal binding protein) is essential for tmRNA (ssrA) function.

85 ral element that is considered essential for tmRNA function based on the analysis of pk1 mutants in v

86 cated E. coli SmpB was likewise inactive for tmRNA translation but was still able to bind ribosomes,

87 statistical analysis revealed that only for tmRNA was the absence nonrandom.

88 somal elements are specifically required for tmRNA activity.

89 ribosomes, indicating two distinct roles for tmRNA-SmpB.

90 Using a genetic selection for tmRNA activity in Escherichia coli, we identified mutati

91 ion of pk1 at 20% per base and selection for tmRNA activity yielded sequences that retain the same ps

92 While ACA motifs are absent from tmRNA, 4.5S RNA, and seven of the eight 5S rRNAs, statis

93 The results show how tmRNA and SmpB act specifically on stalled ribosomes and

94 This evaluation showed that while the hybrid tmRNA supported nascent polypeptide tagging and ribosome

95 We observed that the hybrid tmRNA was active but resulted in less accurate selection

96 propose that the unusual bias against ACA in tmRNA may have coevolved with the acquisition of MazF.

97 We conclude that the role of pk1 in tmRNA function is purely structural and that it can be r

98 -paused ribosomes was slightly more rapid in tmRNA(+) cells (T(1/2)=22+/-2.2 s) than in DeltatmRNA ce

99 mmediately upstream of this coding region in tmRNA, is a structural element that is considered essent

100 the target arginine codons, and resulted in tmRNA-mediated SsrA-peptide tagging of the nascent polyp

101 minal tail of SmpB play an important role in tmRNA accommodation.

102 and PNPase do not play a significant role in tmRNA-facilitated disposal of aberrant mRNAs.

103 n S1 binds tmRNA, but its functional role in tmRNA-mediated tagging is uncertain.

104 ssibility that S1 plays little or no role in tmRNA-mediated tagging.

105 so reveals a tail-dependent role for SmpB in tmRNA translation that supersedes a simple role of linki

106 howed that the discrimination against ACA in tmRNAs was seen mostly in enterobacteria.

107 e to rpsL(P90K) cells but failed to increase tmRNA.SmpB activity.

108 strain, and selective pressure for increased tmRNA activity was indicated by the emergence of mutant

109 ere, we show that deletion of rluD increases tmRNA activity on ribosomes undergoing release factor 2

110 ctivities that are influenced by independent tmRNA and SmpB determinants.

111 ded that the C889U mutation does not inhibit tmRNA activity per se but interferes with an upstream st

112 alling sequence, suggesting that it inhibits tmRNA activity directly.

113 cinating quality-control mechanisms involves tmRNA, also known as SsrA or 10Sa RNA.

114 high temperature because of the role of its tmRNA product in rescuing stalled ribosomes.

115 hemical studies suggest mechanisms that keep tmRNA from interrupting normal translation and target ri

116 In Caulobacter crescentus cells lacking tmRNA activity there is a delay in the initiation of DNA

117 li cells, but accumulates in mutants lacking tmRNA.

118 e developed two genetic selections that link tmRNA activity to cell death.

119 ion that supersedes a simple role of linking tmRNA to the ribosome, which the SmpB body alone could p

120 mponents of the trans-translation machinery, tmRNA, and its associated protein, SmpB, are essential f

121 The introduction of single-strand ACAs makes tmRNA highly susceptible to MazF cleavage.

122 on of an extended Mycoplasma pneumoniae (MP) tmRNA tag by the MP-Lon protease.

123 n can efficiently and selectively degrade MP-tmRNA-tagged proteins.

124 eractions between MP-Lon and the extended MP-tmRNA tag have co-evolved from pre-existing weaker inter

125 eal that the larger (27 amino acids long) MP-tmRNA tag contains multiple discrete signalling motifs f

126 ne encoding ssrA, a hybrid of tRNA and mRNA (tmRNA), which is involved in a trans-translation process

127 Inactivation of transfer mRNA (tmRNA) (encoded by ssrA), coupled with a multicopy kanam

128 cially by overproduction of a non-stop mRNA, tmRNA levels did not increase but tmRNA-mediated tagging

129 Using a mutant tmRNA that encodes a tag that does not lead to degradati

130 e identification of a large number of native tmRNA substrates.

131 egulation of these factors in the absence of tmRNA activity might be responsible for the delay in ini

132 In the absence of tmRNA tagging, truncated ArfA chains are released from t

133 Furthermore, analysis of tmRNA sequences from 442 bacteria showed that the discri

134 The initial binding of tmRNA and its subsequent accommodation into the ribosoma

135 The binding of tmRNA to the stalled ribosome is mediated by small prote

136 Here, we examine how binding of tmRNA-SmpB leads to proteolysis of RNase R.

137 ase protein, resulting in tighter binding of tmRNA-SmpB to the C-terminal region of exponential phase

138 s from acetylation which promotes binding of tmRNA-SmpB, two trans-translation factors, to its C-term

139 uggests that SmpB is a universal cofactor of tmRNA.

140 d by a ribonucleoprotein complex composed of tmRNA, a specialized RNA with properties of both a tRNA

141 protease responsible for the degradation of tmRNA-tagged proteins.

142 participates directly in the degradation of tmRNA-tagged proteins.

143 ATP-dependent protease in the degradation of tmRNA-tagged proteins.

144 stem is the major contributor to disposal of tmRNA-tagged proteins.

145 rowth but causes little if any disruption of tmRNA-mediated tagging.

146 oximately 13 to 15 angstroms of the entry of tmRNA into the ribosome.

147 that are likely to be a universal feature of tmRNA activity in eubacteria.

148 The functions of tmRNA ensure that stalled ribosomes are rescued, the cau

149 ased in cells expressing very high levels of tmRNA and its binding protein SmpB, suggesting that reco

150 lon mutants accumulated excessive levels of tmRNA-tagged proteins.

151 spatially regulate RNAs, the localization of tmRNA was determined using fluorescence in situ hybridiz

152 ArfA (YhdL) is a mediator of tmRNA-independent ribosome rescue that is essential for

153 selection of the reading frame on the ORF of tmRNA.

154 d ribosome fractions only in the presence of tmRNA.

155 Additional biological roles of tmRNA include stress management and the regulation of tr

156 ributes information relevant to the study of tmRNA.

157 -Francisella tularensis chimeric variants of tmRNA and SmpB.

158 d the tagging activity of hybrid variants of tmRNA and the SmpB protein, in which the tmRNA ORF or th

159 polypeptide is transferred to the alanine on tmRNA, and translation switches from the original messag

160 ive message to a short open reading frame on tmRNA that tags the defective nascent peptide chain for

161 ld defective message to the reading frame on tmRNA.

162 oth contribute to reading frame selection on tmRNA.

163 switches templates, resuming translation on tmRNA in the proper reading frame, remains unknown.

164 without interference from A-site cleavage or tmRNA activities.

165 The regulatory RNA SsrA (or tmRNA) has both tRNA and mRNA activities, relieving ribo

166 SsrA, or tmRNA, is a small RNA that interacts with selected trans

167 usually occurs site-specifically at tRNA or tmRNA gene (together, tDNA) targets, catalyzed by tyrosi

168 Integration usually occurs within a tRNA or tmRNA gene, splitting the gene, yet sequences within the

169 teobacteria have one-piece tmRNA, a permuted tmRNA gene was found for Dechloromonas aromatica and clo

170 ereas most betaproteobacteria have one-piece tmRNA, a permuted tmRNA gene was found for Dechloromonas

171 main to that from a cyanobacterial two-piece tmRNA, but such transfer would not appear simple since t

172 cterial lineage with a loop-opened two-piece tmRNA.

173 down to 53 fmol of Streptococcus pneumoniae tmRNA, equivalent to approximately 3.16x10(7) CFU of bac

174 d 2) does SmpB pre-bind ribosomes to recruit tmRNA.

175 Nase R, and localization might also regulate tmRNA-SmpB interactions with ribosomes.

176 l SmpB-stalled ribosome interactions require tmRNA.

177 Cleavage does not require tmRNA, the ribosomal alarmone (p)ppGpp, or bacterial tox

178 on of the free form of RNase R also requires tmRNA-SmpB, but this process is independent of ribosomes

179 lexes in a process termed 'ribosome rescue.' tmRNA.SmpB specifically recognizes ribosomes that are pa

180 e recruitment of the transfer-messenger RNA (tmRNA) (SsrA) quality control system to distressed ribos

181 Transfer-messenger RNA (tmRNA) acts first as a tRNA and then as an mRNA template

182 The transfer-messenger RNA (tmRNA) and its partner protein SmpB act together in reso

183 mechanism involving transfer-messenger RNA (tmRNA) and its protein partner, SmpB.

184 g trans-translation, transfer-messenger RNA (tmRNA) and small protein B (SmpB) together rescue riboso

185 anslation machinery, transfer-messenger RNA (tmRNA) and SmpB, that are responsible for the short half

186 protein B (SmpB) and transfer-messenger RNA (tmRNA) are the two known factors required for and dedica

187 Transfer-messenger RNA (tmRNA) enters stalled translational complexes and, with

188 ication of bacterial transfer-messenger RNA (tmRNA) is presented employing arrays of silicon photonic

189 bacteria, the hybrid transfer-messenger RNA (tmRNA) rescues ribosomes stalled on defective messenger

190 In eubacteria, the transfer-messenger RNA (tmRNA) system facilitates recycling of stalled ribosomes

191 sages are rescued by transfer-messenger RNA (tmRNA), a bifunctional molecule that acts as both a tran

192 mRNAs are rescued by transfer-messenger RNA (tmRNA), a dual-function molecule that contains a tRNA-li

193 Bacteria contain transfer-messenger RNA (tmRNA), a molecule that during trans-translation tags in

194 ence genes 16S rRNA, transfer-messenger RNA (tmRNA), pre-16S rRNA, and rpoB by reverse transcriptase

195 ialized mRNA, called transfer messenger RNA (tmRNA), to rescue such a stalled system.

196 ite component of the transfer messenger RNA (tmRNA)-mediated bacterial translational quality control

197 Transfer-messenger RNA (tmRNA)-SmpB specifically recognizes and resolves nonstop

198 omes is dependent on transfer-messenger RNA (tmRNA)-SmpB, nonstop mRNA, and the modified form of ribo

199 teolytic adaptor for transfer-messenger RNA (tmRNA)-tagged proteins, in Caulobacter crescentus.

200 o the translation of transfer-messenger RNA (tmRNA).

201 hought to facilitate transfer-messenger RNA (tmRNA).SmpB- mediated recycling of stalled ribosome comp

202 Transfer-messenger RNA (tmRNA, or SsrA), found in all eubacteria, has both trans

203 SsrA RNA (tmRNA), a regulatory RNA conserved in all bacteria, is c

204 l RNase P also processes precursor 4.5S RNA, tmRNA, 30S preribosomal RNA, and several reported protei

205 d 2.4 log(10) estimated CFU/ml for 16S rRNA, tmRNA, pre-16S rRNA, and rpoB, respectively.

206 Analysis of select tmRNA variants revealed that the sequence composition an

207 n which tmRNA-SmpB is localized to sequester tmRNA from RNase R, and localization might also regulate

208 witches from the original message to a short tmRNA open reading frame (ORF) that encodes a degradatio

209 like pattern that was separate from the SmpB-tmRNA complex.

210 The SmpB-tmRNA quality control system has evolved to solve proble

211 The SmpB-tmRNA-mediated trans-translation system has two well-est

212 We propose that a 1:1:1 complex of SmpB.tmRNA.EF-Tu(GTP) recognizes and binds a stalled ribosome

213 tly more labile than interaction of the SmpB.tmRNA complex with ribosomes.

214 though essential in a few bacterial species, tmRNA is nonessential in Escherichia coli and many other

215 Species specific tmRNA molecules are targeted by complementary DNA captur

216 onally tagged with a peptide encoded by ssrA/tmRNA (transfer-messenger RNA), which signals their degr

217 Strikingly, tmRNA-mediated SsrA peptide tagging of two proteins, rib

218 construct containing a hard-coded C-terminal tmRNA tag (GFP-SsrA) exhibited increased stability in lo

219 mical and structural data demonstrating that tmRNA is the high-affinity binding partner of SmpB.

220 These results indicate that tmRNA.SmpB activity is rate limited by mRNA cleavage, an

221 Together, these results indicate that tmRNA.SmpB does not suppress transient ribosome pauses,

222 urately replicates the in vivo process, that tmRNA-SmpB is not essential, but it stimulates binding o

223 We propose that tmRNA.SmpB binds to streptomycin-resistant rpsL ribosome

224 We show that tmRNA maintains a stable 'arc and fork' structure on the

225 em is targeted to ribosomes and suggest that tmRNA-tagging is used for both quality control and speci

226 The tmRNA pathway is thought to act only on ribosomes contai

227 The tmRNA sequences are aligned manually, assisted by comput

228 The tmRNA system orchestrates three key biological functions

229 The tmRNA system performs translational surveillance and rib

230 The tmRNA-SmpB system releases ribosomes stalled on truncate

231 o-formed complex containing ribosome and the tmRNA at the point where the TLD is accommodated into th

232 is compromised, A site mRNA cleavage and the tmRNA system provide a mechanism for reducing translatio

233 hewanella isolates harbour a prophage at the tmRNA (ssrA) gene.

234 In bacteria, the tmRNA quality control system recycles these stalled ribo

235 dues that reside at the junction between the tmRNA-binding core and the C-terminal tail of SmpB play

236 ity with Escherichia coli SspB but binds the tmRNA tag in vitro and is required for optimal proteolys

237 led ribosomes in bacteria are rescued by the tmRNA system.

238 hly purified Lon preferentially degraded the tmRNA-tagged forms of proteins compared to the untagged

239 ghlighted the importance of establishing the tmRNA reading frame, and provided valuable clues into th

240 n Escherichia coli and other eubacteria, the tmRNA system rescues stalled ribosomes and adds an ssrA

241 more significant bias in specificity for the tmRNA gene (ssrA) than for any type of tRNA gene.

242 omplex with much improved definition for the tmRNA-SmpB complex, showing two SmpB molecules bound per

243 addition to its quality-control function the tmRNA system might also play a key regulatory role in ce

244 Furthermore, the tmRNA pathway is activated upon aza-C treatment in cells

245 Recent studies clarify how the tmRNA system is targeted to ribosomes and suggest that t

246 We found that mutants defective in the tmRNA translational quality control system are hypersens

247 y, the centroid of the RNA-like group is the tmRNA fold, a pseudoknot having both tRNA-like and mRNA-

248 Transcription of the tmRNA gene, however, was significantly up-regulated duri

249 proper positioning and establishment of the tmRNA open reading frame (ORF) as the surrogate template

250 hese data suggest that the engagement of the tmRNA ORF and the selection of the correct translation r

251 at an early stage after establishment of the tmRNA ORF as the surrogate mRNA template.

252 f the ultimate and penultimate codons of the tmRNA ORF play a crucial role in recruiting RNase R to r

253 Modifications of the tmRNA tag and use of higher-resolution mass spectrometry

254 ntegrity and the proteolytic function of the tmRNA tag are both crucial for normal growth and virulen

255 lly linked with the sequence upstream of the tmRNA template; both contribute to reading frame selecti

256 a high level of activity on the part of the tmRNA trans translation system.

257 r initiation of DNA replication, most of the tmRNA was degraded, and the remaining molecules were spr

258 ribosomes by facilitating recruitment of the tmRNA*SmpB ribosome rescue system.

259 ne the structures of three key states of the tmRNA-SmpB-ribosome complex during trans translation at

260 ity map for the preaccommodated state of the tmRNA.SmpB.EF-Tu.70S ribosome complex with much improved

261 This process requires the tmRNA-binding and ribosome-binding cofactor SmpB, a beta

262 These results argue that the tmRNA pathway clears stalled ribosome-mRNA complexes gen

263 Occupying the empty A site with its TLD, the tmRNA enters the ribosome with the help of elongation fa

264 t ArfA homologues are only deployed when the tmRNA system is incapacitated or overwhelmed by stalled

265 of tmRNA and the SmpB protein, in which the tmRNA ORF or the SmpB C-terminal tail was substituted wi

266 A site of the ribosome and explains why the tmRNA-SmpB system does not interfere with normal transla

267 pB sequences which are served along with the tmRNA sequence from the same organism.

268 rescue, the nascent chain is tagged with the tmRNA-encoded ssrA peptide, which promotes polypeptide d

269 rescue, the nascent chain is tagged with the tmRNA-encoded ssrA peptide, which targets the tagged pol

270 Within the tmRNA sequence itself, five nucleotides (U85AGUC) immedi

271 Lists of the tmRNAs and the corresponding tmRNA-encoded tag-peptides

272 Three-dimensional models of the tmRNAs and their associated proteins in PDB format give

273 This tmRNA activity results from sequestration of prolyl-tRNA

274 t ties the life of Escherichia coli cells to tmRNA activity.

275 The binding of S1 and its fragments to tmRNA and mRNA is positively cooperative, and the essent

276 ir ubiquitous colocalization with respect to tmRNA merits further examination.

277 t for the binding of ribosomal protein S1 to tmRNA.

278 translation complexes in a manner similar to tmRNA-SmpB recognition and directly hydrolyzes the pepti

279 d that SmpB, a protein that binds tightly to tmRNA, was colocalized with tmRNA in the helix-like patt

280 Mimicking a tRNA, tmRNA enters stalled ribosomes, adds Ala to the nascent

281 Correspondingly, two tmRNA pieces were identified, at approximately equal abu

282 The peptide tag encoded by wild-type tmRNA promotes rapid degradation of rescued proteins.

283 agging site, which is required for wild-type tmRNA tagging.

284 nces, an update raising the number of unique tmRNA sequences from 492 to 1716, and a database of SmpB

285 e stalled mRNA and resumes translation using tmRNA as a template, adding a short peptide tag that des

286 pid identification of different bacteria via tmRNA profiling.

287 However, the mechanism by which tmRNA can enter and move through the ribosome is unknown

288 These results suggest a model in which tmRNA-SmpB is localized to sequester tmRNA from RNase R,

289 nic (31%) or intragenic (28%) regions, while tmRNAs were targeted in 8% of the regions.

290 , a phenotype not previously associated with tmRNA activity.

291 Proteins known to be associated with tmRNA include SmpB, ribosomal protein S1, RNase R, and p

292 binds tightly to tmRNA, was colocalized with tmRNA in the helix-like pattern.

293 e assess the capacity of POA to compete with tmRNA for RpsA.

294 bosomal protein S1 (RpsA) and competing with tmRNA, the natural cofactor of RpsA.

295 , a small protein that works in concert with tmRNA.

296 ite and may make base-specific contacts with tmRNA ligands.

297 0 S ribosomes SmpB partitions primarily with tmRNA rather than ribosomal subunits.

298 the importance of coupling proteolysis with tmRNA-mediated tagging and ribosome rescue.

299 Furthermore, RqcH acts redundantly with tmRNA/ssrA and protects cells against translational and

300 ts mRNA template and resume translation with tmRNA itself as a template.