ライフサイエンスコーパス: riboswitch

1 ive riboswitch (P(tac)-riboswitch and P(BAD)-riboswitch).

2 lorimetry, explaining the specificity of the riboswitch.

3 ry site (IRES) and the flavin-mononucleotide riboswitch.

4 ine riboswitch and as the second for the ZMP riboswitch.

5 d metabolite-bound closed state of the SAM-I riboswitch.

6 e folding free energy landscape of the SAM-I riboswitch.

7 folding free energy landscape of the SAM-II riboswitch.

8 s strong co-transcriptional effects for this riboswitch.

9 and the P3 helix is a bottleneck in the apo riboswitch.

10 7-aminomethyl-7-deazaguanine (preQ1)-sensing riboswitch.

11 is distinctly different from that in the apo riboswitch.

12 evealed new tertiary interactions in the TPP riboswitch.

13 n-coding RNAs: 5S rRNA, RNase P and the btuB riboswitch.

14 positive bacteria are regulated by the T box riboswitch.

15 edge, of translational regulation in a T box riboswitch.

16 P(tac) > P(BAD) > P(BAD)-riboswitch > P(tac)-riboswitch.

17 orce spectroscopy trajectory for multi-state riboswitch.

18 ding landscape that controls the fate of the riboswitch.

19 le RNA and the Bacillus cereus crcB fluoride riboswitch.

20 omeostasis is controlled by yybP-ykoY family riboswitches.

21 Gram-positive bacteria is monitored by T-box riboswitches.

22 egion (UTR) derives from bacterial and other riboswitches.

23 regulation implemented by a wide variety of riboswitches.

24 t in Archaea is controlled by FMN-responsive riboswitches.

25 development of efficient cis-acting aptazyme riboswitches.

26 ersity of naturally occurring ligand-binding riboswitches.

27 t the structures of apo and SAM-bound SAM-IV riboswitches (119-nt, ~40 kDa) to 3.7 angstrom and 4.1 a

28 strand-specific RNA sequencing to identify 4 riboswitches, 13 trans-acting (intergenic), and 22 cis-a

29 standard inducible promoters and orthogonal riboswitches, a multi-layered modular genetic control ci

30 ap, we prepared 15 mutants of the preQ(1)-II riboswitch-a structurally and biochemically well-charact

31 macromolecular crowding collectively control riboswitch activation.

32 cted toward the identification of artificial riboswitch activators by establishing high-throughput sc

33 A T-box regulator or riboswitch actively monitors the levels of charged/uncha

34 Furthermore, the ligands modulate riboswitch activity through transcriptional termination

35 This riboswitch allowed reversible, theophylline-dependent do

36 Pre-organization of the SAM-II riboswitch allows rapid detection of ligand with high se

37 ong evidence that translationally regulating riboswitches also regulate mRNA levels through an indire

38 Riboswitches alter gene expression in response to ligand

39 A majority of riboswitches, an important class of small metabolite-sen

40 he aptamer domain of this atypical cobalamin riboswitch and a model for the complete riboswitch, incl

41 first of all submissions for the L-glutamine riboswitch and as the second for the ZMP riboswitch.

42 structure upstream of the characterized HIV riboswitch and demonstrates the basal translation rate o

43 s ON-OFF transition of the full length SAM-I riboswitch and its magnesium concentration dependence.

44 l theophylline-responsive riboswitch (P(tac)-riboswitch and P(BAD)-riboswitch).

45 ession platform of the P3 helix in the bound riboswitch and the P3 helix is a bottleneck in the apo r

46 ed allosteric switching" is proposed to link riboswitch and translation regulation.

47 ional interactions-e.g., at switch points in riboswitches and at a complex nucleation site in HIV.

48 ensing on tRNAs and gene regulation by T-box riboswitches and exemplify how higher-order RNA-RNA inte

49 ross species, which correspond to many known riboswitches and further suggest novel putative regulato

50 ecent studies have identified new classes of riboswitches and have revealed new insights into the mol

51 ods that have been developed to engineer new riboswitches and highlight applications of natural and s

52 esistance genes including metabolite-binding riboswitches and other transcription attenuators.

53 chemical and biological sciences, including riboswitches and riboregulators.

54 ble to modulate gene expression as shown for riboswitches and RNA thermometers.

55 l as the prevalence of mRNA leaders that use riboswitches and RNA-binding proteins.

56 n streamlines design of synthetic allosteric riboswitches and small molecule-nucleic acid complexes.

57 ural analyses between conventional cobalamin riboswitches and the B. subtilis cobalamin riboswitch re

58 By harnessing fluoride-responsive riboswitches and the orthogonal T7 RNA polymerase, bioch

59 B. subtilis at a global level by binding to riboswitches and to different classes of transport prote

60 from four classes of k-turns from ribosomes, riboswitches and U4 snRNA, finding a strong conservation

61 long-lost ligand sensed by the ykkC class of riboswitches, and identified that members of its regulon

62 nal strategies that are applied by aptamers, riboswitches, and ribozymes/DNAzymes.

63 This SAM-I riboswitch appears to be highly conserved in Xanthomonas

64 of the streptomycin aptamer into functional riboswitches appears to be difficult.

65 These findings reveal that a riboswitch aptamer can function independently of any ove

66 ions were used to target the guanine-sensing riboswitch aptamer domain (GSR(apt)) of the xpt-pbuX ope

67 We show that the mgtA riboswitch aptamer domain adopts a canonical yybP-ykoY s

68 y determining four structures of the adenine riboswitch aptamer domain during the course of a reactio

69 ring ligand recognition of the preQ1 class-I riboswitch aptamer from Thermoanaerobacter tengcongensis

70 stal structure of the ligand-bound yybP-ykoY riboswitch aptamer from Xanthomonas oryzae at 2.96 angst

71 highly extended conformations of an adenine riboswitch aptamer.

72 Ligand binding by other riboswitch aptamers peripheral to the path traveled by R

73 cholerae and Fusobacterium nucleatum glycine riboswitch aptamers with and without glycine, Mycobacter

74 yclic-di-GMP, glycine, and adenosylcobalamin riboswitch aptamers without their ligands and a loose st

75 structured RNAs including ribozyme domains, riboswitch aptamers, and viral RNA domains with a single

76 nthetic small molecules that bind to PreQ(1) riboswitch aptamers.

77 Riboswitches are a class of metabolism control elements

78 Riboswitches are a class of nonprotein-coding RNAs that

79 Riboswitches are a widely distributed class of regulator

80 Riboswitches are cis-acting regulatory RNA biosensors th

81 Riboswitches are cis-regulatory elements in mRNA, mostly

82 Riboswitches are common gene regulatory units mostly fou

83 However, a significant proportion of glycine riboswitches are comprised of single aptamers (singleton

84 The ligand recognition mechanisms of riboswitches are diverse, but we find that they share a

85 irillum indicum The regulatory mechanisms of riboswitches are influenced by the kinetics of ligand in

86 T-box riboswitches are modular bacterial noncoding RNAs that s

87 Riboswitches are naturally occurring RNA aptamers that r

88 Riboswitches are regulatory elements that control gene e

89 Riboswitches are RNA elements that act on the mRNA with

90 Riboswitches are RNAs that form complex, folded structur

91 Riboswitches are shape-changing regulatory RNAs that bin

92 Riboswitches are small cis-regulatory RNA elements that

93 s, the ligand-mediated folding mechanisms of riboswitches are still poorly understood.

94 Riboswitches are structural genetic regulatory elements

95 Riboswitches are structural RNA elements that are genera

96 Riboswitches are structured ncRNAs that directly interac

97 Riboswitches are structured RNA motifs that recognize me

98 Riboswitches are thought generally to function by modula

99 Riboswitches are widespread RNA motifs that regulate gen

100 rRNA, and the aptamer domain of the adenine riboswitch) are in excellent agreement with experiments

101 pseudoknot of a class-I translational preQ1 riboswitch as a highly structured RNA model whose confor

102 rize the Lactococcus lactis yybP-ykoY orphan riboswitch as a Mn(2+)-dependent transcription-ON ribosw

103 These results establish artificial riboswitches as tools for externally controlled gene exp

104 ussed in light of their existence in adenine riboswitches, as well as the turnip yellow mosaic virus

105 ach for the design of synthetic theophylline riboswitches based on secondary structure prediction.

106 Our riboswitch-based biosensors required an alternate invert

107 Many riboswitches bind protein enzyme cofactors that, in prin

108 ssment of the translational potential of FMN riboswitch binders against wild-type Gram-negative bacte

109 We demonstrate that this riboswitch binds to multiple cobalamin derivatives and c

110 determined crystal structures of the SAM/SAH riboswitch bound to SAH, SAM and other variant ligands a

111 SAM-IV are the three most commonly found SAM riboswitches, but the structure of SAM-IV is still unkno

112 ve analyzed the ligand-binding properties of riboswitches, but this work has outpaced our understandi

113 dated as a second class of 2'-deoxyguanosine riboswitch (called 2'-dG-II).

114 transcriptional RNA, the translational metI riboswitch can make multiple reversible regulatory decis

115 at the two alternate secondary structures of riboswitches can be accurately predicted once the 'switc

116 ption of essential genes controlled by T-box riboswitches can be directly modulated by commonly used

117 f the ykkC motif RNA, the longest unresolved riboswitch candidate, naturally sense and respond to gua

118 s pipeline that can uncover novel, but rare, riboswitch candidates as well as other noncoding RNA str

119 ure and mutagenesis analyses revealed a VB12-riboswitch, cbiMCbl (140 bp), within the 5' UTR that con

120 ogical function, which has ramifications for riboswitch characterization.

121 NA-mediated regulators (e.g., thermosensors, riboswitches, cis- and trans-encoded RNAs) used for adap

122 scoveries are unique variants of the guanine riboswitch class that most tightly bind the nucleoside 2

123 ition, we identified variants of the glycine riboswitch class that no longer recognize this amino aci

124 roups of protein enzymes and receptors, some riboswitch classes have evolved to change their ligand s

125 a procedure to systematically analyze known riboswitch classes to find additional variants that have

126 overing a large number of additional natural riboswitch classes.

127 ls in Gram--negative bacteria, translational riboswitches--commonly embedded in messenger RNAs (mRNAs

128 been fine-tuned for its particular role as a riboswitch component.

129 Thus, Spinach riboswitches constitute a novel class of RNA-based fluor

130 the utility of the tightly inducible P(BAD)-riboswitch construct using the dynamic activity of type

131 Riboswitches control the expression of essential bacteri

132 uggesting that the majority of known E. coli riboswitches control transcription termination by using

133 Stable genetic deletion or riboswitch-controlled depletion results in spherical cel

134 the underlying chemical pathways that govern riboswitch-controlled gene expression.

135 functional analysis in live bacteria using a riboswitch-controlled GFPuv-reporter assay revealed that

136 The widespread Mn(2+)-sensing yybP-ykoY riboswitch controls the expression of bacterial Mn(2+) h

137 Known primarily from bacteria, riboswitches couple specific ligand binding and changes

138 same RNA structural transitions related to a riboswitch decision-making process that we previously id

139 er, our findings suggest that tandem glycine riboswitches degrade into functional singletons, with th

140 ertiary structural interactions in cobalamin riboswitches dictate ligand selectivity.

141 olving mechanisms such as dynamic folding of riboswitches during translation initiation or the synthe

142 f the phylogenetically widespread classes of riboswitches, each specific to a particular metabolite o

143 This riboswitch-effector interplay produces a layer of gene r

144 Cobalamin riboswitches encompass a structurally diverse group of c

145 HMP-PP riboswitches exhibit a distinctive architecture wherein

146 The resulting tetracycline riboswitches exhibit robust regulatory properties in viv

147 h > P(BAD); while the newly developed P(BAD)-riboswitch exhibited no detectable leakiness.

148 ngle-molecule FRET analysis reveals that the riboswitch exists in two distinct conformations, and tha

149 has been very successful in identifying new riboswitch families and defining their distributions, sm

150 cture similar to other members of the purine riboswitch family, but contains key differences within t

151 We review how riboswitch folds adhere to this fundamental strategy and

152 VB12, illuminating the significance of this riboswitch for bacterial VB12 biosynthesis.

153 n plastids, but the application of synthetic riboswitches for the regulation of nuclear-encoded genes

154 t broadly distributed and numerous bacterial riboswitches for which the cognate ligand was unknown.

155 The riboswitch forms an H-type pseudoknot structure with coa

156 iron responsive elements (29 nt), a fluoride riboswitch from Bacillus anthracis(48 nt), and a frame-s

157 d approach was used to re-engineer the PreQ1 riboswitch from Bacillus subtilis into an orthogonal OFF

158 e show that for the guanine-sensing xpt-pbuX riboswitch from Bacillus subtilis, the conformation of t

159 sed readouts of 15 mutants of the preQ(1)-II riboswitch from Lactobacillus rhamnosus demonstrates tha

160 ion by the aptamer domain of a guanidine III riboswitch from Legionella pneumophila has a different e

161 ide resolution for the I-A type 2'dG-sensing riboswitch from Mesoplasma florum by NMR spectroscopy.

162 case of the thiamine 5'-pyrophosphate (TPP) riboswitch from the Escherichia coli thiM gene encoding

163 hich targets the flavin mononucleotide (FMN) riboswitch, from a compound lacking whole-cell activity

164 pling of synthesis and folding essential for riboswitch function, revealing the importance of metasta

165 ing RNA synthesis is important to understand riboswitch function.

166 d thereby affects the molecular mechanism of riboswitch function.

167 xhibit Mn2+ sensitivity, revealing that this riboswitch functions as a failsafe 'on' signal to preven

168 lts suggest that the S. pneumoniae yybP-ykoY riboswitch functions to regulate Ca2+ efflux under these

169 tomic-resolution structural information, and riboswitch gene associations.

170 and show that leakiness for P(tac) > P(tac)-riboswitch > P(BAD); while the newly developed P(BAD)-ri

171 duction varied with P(tac) > P(BAD) > P(BAD)-riboswitch > P(tac)-riboswitch.

172 In rare instances, ligand binding to a riboswitch has been found to alter the rate of RNA degra

173 edicted once the 'switching sequence' of the riboswitch has been properly identified.

174 epresentative members of the SAM-I family of riboswitches has been extensively analyzed using approac

175 genic approach to demonstrate that cobalamin riboswitches have a broad spectrum of preference for the

176 These riboswitches have been constructed to regulate ligand-de

177 Numerous classes of riboswitches have been discovered, enabling mRNA to be r

178 Synthetic riboswitches have been engineered as versatile and innov

179 alian gene expression with ligand-responsive riboswitches have been hindered by lack of a general met

180 ntal importance in bacteria gene regulation, riboswitches have been proposed as antibacterial drug ta

181 Although Bacillus subtilis riboswitches have been shown to control premature transc

182 inomethyl-7-deazaguanine, preQ(1)) bacterial riboswitches have been studied, but the functional conse

183 Mg2+ ions suggests that some single-aptamer riboswitches have exploited the coupling of cellular lev

184 Riboswitches have gained attention as tools for syntheti

185 uggests the need for alternative methods for riboswitch identification, possibly based on features in

186 g data for the Bacillus subtilis glyQS T-box riboswitch in complex with an uncharged tRNAGly.

187 e determined crystal structures of a preQ1-I riboswitch in effector-free and bound states at 2.00 ang

188 closed and open conformations of the SAM-II riboswitch in the absence of ligand.

189 ure of the eukaryotic thiamine pyrophosphate riboswitch in the context of a hexanucleotide loop seque

190 fied and characterized a translational S-box riboswitch in the metI gene from Desulfurispirillum indi

191 MN-induced "turn-off" activities of both FMN riboswitches in Bacillus subtilis, allowing rib gene exp

192 hlight applications of natural and synthetic riboswitches in enzyme and strain engineering, in contro

193 single-molecule monitoring captures folding riboswitches in multiple states, including an intermedia

194 amin riboswitch and a model for the complete riboswitch, including its expression platform domain.

195 S-box (SAM-I) riboswitches, including the riboswitch present in the Ba

196 Ligand binding to the aptamer domain of the riboswitch induces premature termination of the mRNA syn

197 Insertion of the riboswitch into the ONE HELIX PROTEIN1 gene allowed comp

198 The S-adenosylmethionine (SAM)-I riboswitch is a noncoding RNA that regulates the transcr

199 The glycine riboswitch is among the most well-studied due to the wid

200 st that the correlation network in the bound riboswitch is distinctly different from that in the apo

201 We demonstrate that the ZTP riboswitch is kinetically controlled and that its activa

202 esented whereby in the absence of ligand the riboswitch is largely unfolded, lacking the PK helix so

203 Defining the 2'-dG-II riboswitches is a two-nucleotide insertion in the three-

204 A rarer class of S-box riboswitches is predicted to regulate translation initia

205 The defining feature of riboswitches is that they directly recognize a physiolog

206 One of the most studied riboswitches is the Bacillus subtilis adenine-responsive

207 plays a key role in folding of ribozymes and riboswitches, is not addressed in most algorithms.

208 determined the structure of the glutamine-II riboswitch ligand binding domain using X-ray crystallogr

209 ene expression by cis-acting transcriptional riboswitches located in the 5'-untranslated regions of m

210 The aptamer portion of the riboswitch may adopt an open or closed state depending o

211 nosine, suggesting that a subset of 2'-dG-II riboswitches may bind either molecule to regulate gene e

212 However, during the riboswitch mediated transcription regulation process, th

213 T box riboswitch-mediated gene regulation was shown previously

214 control by the cyclic AMP receptor protein, riboswitch-mediated transcription attenuation in respons

215 h previously and newly discovered classes of riboswitches might reveal subgroups of RNAs that respond

216 edict toehold switch function as a canonical riboswitch model in synthetic biology.

217 tructured, cis-encoded RNA elements known as riboswitches modify gene expression upon binding a wide

218 many of these changes are not present in TPP riboswitch mutant plants, demonstrating their lack of me

219 described Arabidopsis (Arabidopsis thaliana) riboswitch mutant plants, which accumulate thiamin vitam

220 n photorespiration and the TCA cycle, as TPP riboswitch mutants accumulate less photorespiratory inte

221 otosynthetic and metabolic phenotypes of TPP riboswitch mutants are photoperiod dependent.

222 We show that TSS reveals riboswitches, non-coding RNA and novel transcription uni

223 on, ligand-jump experiments reveal imperfect riboswitching of single mRNA molecules.

224 The discovery, design and reengineering of riboswitches offer an alternative means by which to cont

225 yielding new information about how different riboswitches operate.

226 The use of riboswitches or proteins to regulate transcription via s

227 Although there are a handful of known riboswitches, our knowledge in this field has been great

228 vailable to support tasks like the design of riboswitches; our analysis of RS3 suggests strong co-tra

229 t have an additional theophylline-responsive riboswitch (P(tac)-riboswitch and P(BAD)-riboswitch).

230 show that one aptamer of the tandem glycine riboswitch pair is typically much more highly conserved,

231 S-box (SAM-I) riboswitches, including the riboswitch present in the Bacillus subtilis metI gene, w

232 NusG-dependent pausing in the ribD riboswitch provides time for cotranscriptional binding o

233 eling at three independent positions on each riboswitch, PRRSM accurately classified all apo and liga

234 Our model-based approach for engineering riboswitches quantitatively confirms several physical me

235 i-AMP molecules are bound to the protein and riboswitch receptors and what kinds of interactions acco

236 To understand how 2'-dG-II riboswitches recognize their cognate ligand and how they

237 y, it is less clear how the unbound, sensing riboswitch refolds into the ligand binding-induced outpu

238 In bacteria, riboswitches regulate sulfur metabolism through binding

239 Investigations of most riboswitches remain confined to the ligand-binding aptam

240 -binding properties, on the widespread T-box riboswitches, remain unknown.

241 ever, the regulation mechanism for the preQ1 riboswitch remains unclear.

242 igands, but their conversion into functional riboswitches remains difficult.

243 Using genetic knockouts, riboswitch reporters, and RNA-Seq, we show that GacA, th

244 ions of these riboswitches with theophylline riboswitches represent logic gates responding to two dif

245 The majority of riboswitches respond to cellular metabolites, often in a

246 iscriminate between SAM and SAH, the SAM/SAH riboswitch responds to both ligands with similar apparen

247 n riboswitches and the B. subtilis cobalamin riboswitch reveal that the likely basis for this promisc

248 bolite, a Mg(2+) (0-0.5 mm)-bound apo SAM-II riboswitch RNA exists in a minor ( approximately 10 %) p

249 sequentially releases fluorescently labeled riboswitch RNA from a heteroduplex in a 5'-to-3' directi

250 sing of changes in the environment by use of riboswitches (RNAs that change shape in response to envi

251 ures are functionally relevant in ribozymes, riboswitches, rRNA, and during replication.

252 rationally designed, artificial theophylline riboswitch RS3.

253 Here, we characterize a SAM-I riboswitch (SAM-I(Xcc)) from the Xanthomonas campestris

254 pproach can also be paired to homology-based riboswitch searches.

255 itching sequence inside a putative, complete riboswitch sequence, on the basis of pairing behaviors,

256 While most SAM riboswitches strongly discriminate between SAM and SAH,

257 range tertiary interactions stabilize global riboswitch structure and confer increased ligand specifi

258 be used as a general strategy in studies of riboswitch structure-function relationship.

259 curately classified all apo and ligand-bound riboswitch structures, including changes in the size of

260 econdary structure level within two distinct riboswitch structures.

261 t there is a great diversity of undiscovered riboswitches, suggests the need for alternative methods

262 r how their sequence controls the physics of riboswitch switching and activation, particularly when c

263 in vivo functional analysis showed that the riboswitch, termed Werewolf-1 (Were-1), inhibits transla

264 on-native, idiosyncratic conformation of the riboswitch that inhibits c-di-GMP binding.

265 nal map of the Vibrio vulnificus add adenine riboswitch that reveals five classes of structures.

266 e used in vitro selection to isolate a novel riboswitch that selectively binds the trans isoform of a

267 tion relationship for translation-regulating riboswitches that activate gene expression, characterize

268 ass, and also variants of c-di-GMP-I and -II riboswitches that might recognize different bacterial si

269 Re-engineered riboswitches that no longer respond to cellular metaboli

270 s the latest gene expression-regulating mRNA riboswitches that respond to the alarmone ppGpp, to PRPP

271 tomated computational design of 62 synthetic riboswitches that used six different RNA aptamers to sen

272 There are a number of riboswitches that utilize the same ligand-binding domain

273 Unlike 2'-dG-I riboswitches, the 2'-dG-II class only requires local cha

274 Ribo-attenuators allow riboswitches to be treated as truly modular and tunable

275 different combinations of TALE proteins and riboswitches, to rapidly and reproducibly control the ex

276 n, ligand binding to the aptamer domain of a riboswitch triggers a signal to the downstream expressio

277 ic analysis of well-characterized classes of riboswitches uncovered subgroups unable to bind to the r

278 Riboswitches undergo cotranscriptional switching in the

279 Here, we characterize a yybP-ykoY family riboswitch upstream of the mgtA gene encoding a PII-type

280 All known riboswitches use their aptamer to senese one metabolite

281 eraction found in the tetrahydrofolate (THF) riboswitch using rationally designed self-assembling tec

282 ch by analyzing the fluorescence response of riboswitch variants, each with a single, strategically p

283 te stress-sensing Fusobacterium ulcerans ZTP riboswitch, we apply a single-molecule vectorial folding

284 of the thiamin pyrophosphate-dependent thiM riboswitch, we find that Rho-dependent transcription ter

285 To overcome the associated difficulties with riboswitches, we have designed and introduced a novel ge

286 dentified class of 2'-deoxyguanosine binding riboswitches, we have solved the crystal structure of a

287 Entropy values of a diverse set of riboswitches were compared to that of their mutants, the

288 In plants, synthetic riboswitches were used to regulate gene expression in pl

289 ation to a model RNA: the core glmS ribozyme riboswitch, which performs a ligand-dependent self-cleav

290 he Bacillus subtilis adenine-responsive pbuE riboswitch, which regulates gene expression at the trans

291 -AMP binds to a large number of proteins and riboswitches, which are often involved in potassium and

292 tory mechanisms employed by Escherichia coli riboswitches, which are predicted to regulate mostly at

293 convertible RNA conformations, as known from riboswitches, which might act as a flux sensor.

294 t is able to model the switching behavior of riboswitches whose generated ensemble covers both altern

295 These findings identify a SAM-I riboswitch with a dual functioning expression platform t

296 th and without glycine, Mycobacterium SAM-IV riboswitch with and without S-adenosylmethionine, and th

297 An unusual variant of the cobalamin riboswitch with predicted structural features was identi

298 itable targets for construction of synthetic riboswitches with design approaches based on equilibrium

299 Tandem fusions of these riboswitches with theophylline riboswitches represent lo

300 witch as a Mn(2+)-dependent transcription-ON riboswitch, with a approximately 30-40 muM affinity for

301 hetic ligands and drugs that bind tightly to riboswitches without eliciting a biological response.