ライフサイエンスコーパス: UGA

1 UGA appears not to function as a stop codon and is in eq

2 UGA codon reassignment renders SR1 genes untranslatable

3 UGA translation as selenocysteine is absolutely dependen

4 Its mRNA contains 10 UGAs in an open reading frame terminated by a UAA.

5 and approaches 100% efficiency at distal 3' UGAs.

6 We show that oyster SelenoP mRNA with 46 UGAs is translated full-length in vivo.

7 ing uORFs and nucleotide motifs, such as '5'-UGA(C/G)GG-3', are found in 5' leader regions of regulat

8 tRNA((cmo)5)UGA(Ser) recognizes UCA, UCG, and UCU codons, but UCU is

9 thin the D-stem of the essential tRNA((cmo)5)UGA(Ser) species.

10 on is specifically recognized by tRNA((cmo)5)UGA(Ser).

11 A UGA codon and a selenocysteine insertion sequence in the

12 e the unusual amino acid selenocysteine at a UGA codon, which conventionally serves as a termination

13 ational incorporation of selenocysteine at a UGA codon.

14 Sec is encoded by a UGA codon in the selenoprotein mRNA.

15 ntain a selenocysteine residue, encoded by a UGA codon, as the penultimate carboxyl-terminal amino ac

16 carboxyl terminus and which is encoded by a UGA codon.

17 Selenocysteine is coded by a UGA stop codon in combination with a specific downstream

18 me of these frameshifted sequences contain a UGA (opal) termination codon.

19 lutathione peroxidase 1 (Se-GPx1) contains a UGA codon that is recognized as a codon for the nonstand

20 that the percentage of ribosomes decoding a UGA codon as selenocysteine rather than termination can

21 n, we used a reporter gene system that has a UGA codon within the protein-coding region of the lucife

22 of selenoproteins requires the decoding of a UGA codon as selenocysteine (Sec) instead of translation

23 proteins via the translational recoding of a UGA codon, normally used as a stop signal.

24 karyotic proteins requires the recoding of a UGA stop codon as one specific for Sec.

25 actors are necessary for "read-through" of a UGA stop codon that specifies selenocysteine incorporati

26 non-structural proteins via readthrough of a UGA stop codon.

27 Functional evidence for the absence of a UGA suppressor tRNA in the cytosol, using a reporter gen

28 e conductance regulator (CFTR) W1282X PTC (a UGA codon) in the context of its three upstream and down

29 3' UTR of selenoprotein genes and recodes a UGA codon within the coding sequence.

30 translational cofactors to "read-through" a UGA-stop codon that specifies SEC incorporation at the a

31 1 (NF1) mRNA changes an arginine (CGA) to a UGA translational stop codon, predicted to result in tra

32 ocysteine incorporation element along with a UGA codon into a reporter construct allows for read-thro

33 n loss of ribosome density downstream of all UGA-Sec codons.

34 verexpressing eRF1 and eRF3, and of altering UGA codon context, on the efficiency of selenoprotein sy

35 teine Insertion Sequence (SECIS) element and UGA codon are sufficient for selenocysteine (Sec) insert

36 These changes, UAR to glutamine and UGA to cysteine, imply that eukaryotic release factor 1

37 nd overexpression of the cysteine mutant and UGA-terminated proteins in the baculovirus insect cell s

38 c ribosome distinguishes between UGA/Sec and UGA/stop codons are discussed.

39 a coli glutamine tRNA, suppress UAG, UAA and UGA termination codons, respectively, in a reporter mRNA

40 Redefinition of UAG, UAA and UGA to specify a standard amino acid occurs in response

41 each of the three stop codons (UAG, UAA, and UGA) and facilitates release of the nascent polypeptide

42 its a preference for the stop codons UAG and UGA and sense codons CAG and UCG in vitro.

43 nse variant erroneously read through UAG and UGA stop codons of mRNAs.

44 tandard genetic code recognize UAA, UAG, and UGA as stop codons, whereas variant code species frequen

45 by any one of the stop codons UAA, UAG, and UGA moving into the ribosomal A site.

46 As UGA is normally a translational stop signal, selenoprote

47 coli 23S rRNA were characterized in vivo as UGA-specific nonsense suppressors.

48 on in eukaryotes occurs cotranslationally at UGA codons via the interactions of RNA-protein complexes

49 r at UAA or UAG PTCs and Trp, Arg, or Cys at UGA PTCs.

50 Selenocysteine (Sec) is incorporated at UGA codons in mRNAs possessing a Sec insertion sequence

51 that Sec is more efficiently incorporated at UGA codons positioned in the middle of the coding region

52 Selenocysteine incorporation at UGA codons requires cis-acting mRNA secondary structures

53 -kDa GFP/GPX1 proteins, Sec incorporation at UGA codons, formerly close to the 5' or 3' ends, was inc

54 demonstrated that the amino acid inserted at UGA because of the prfB1 mutations was tryptophan.

55 , whereas Trp, Arg, and Cys were inserted at UGA, and the frequency of insertion of individual amino

56 ed due to varying errors in Sec insertion at UGA.

57 nthesis and insertion of Cys into protein at UGA codons and suggest new biological functions for thio

58 In addition, readthrough at UGA was observed when the viral SECIS element was locate

59 and distinct roles for SECIS1 and SECIS2 at UGA codons.

60 Since termination at UGA in E. coli specifically requires release factor 2 (R

61 lease factor 2 (RF2)-mediated termination at UGA stop codons.

62 ates more efficiently at UAG and UAA than at UGA.

63 Cys was inserted in vivo at UGA codons in natural mammalian TRs, and this process wa

64 res the reprogramming of translation because UGA is normally read as a stop codon.

65 to the primary sequence arrangement between UGA codons and SECIS elements, their proximity within th

66 steine incorporation as the distance between UGA codons is increased, and that efficient selenocystei

67 he eukaryotic ribosome distinguishes between UGA/Sec and UGA/stop codons are discussed.

68 ryptophan, cysteine, and arginine decoded by UGA and thus arise by suppression.

69 Sec and Pyl are encoded by UGA and UAG codons, respectively, which normally serve a

70 nd twenty second amino acids, are encoded by UGA and UAG, respectively, which are the codons that usu

71 are amino acid in protein that is encoded by UGA with the requirement of a downstream mRNA stem-loop

72 Selenocysteine (Sec or U) is encoded by UGA, a stop codon reassigned by a Sec-specific elongatio

73 e (Sec), a nonstandard amino acid encoded by UGA, normally a stop codon.

74 he 21st amino acid in protein, is encoded by UGA.

75 form of a selenocysteine residue encoded by UGA.

76 ncy of Sec incorporation can be modulated by UGA position; Sec incorporation at high efficiency appea

77 Sec specification by UGA codons requires the presence of a cis-acting selenoc

78 FliK synthesized by UGA readthrough could be detected when overproduced from

79 Furthermore, the deletion was found to cause UGA readthrough on its own, thereby implicating helix 73

80 also confirm here a previous report that CCC UGA is a translational frameshift site, in these experim

81 We cloned, UGA corrected, expressed, purified, and demonstrated tha

82 In the genetic code, UGA serves as a stop signal and a selenocysteine codon,

83 d that recognized specifically the Sec codon UGA.

84 ted into proteins by recoding the stop codon UGA from termination to selenocysteine insertion.

85 We found that the codon UGA specifies insertion of selenocysteine and cysteine i

86 ted into selenoproteins in response to codon UGA with the help of the selenocysteine insertion sequen

87 the 3'-untranslated region and a Sec codon (UGA) in the coding region.

88 dons, UGU and UGC, as well as the Sec codon, UGA.

89 e (Sec), which is encoded by the stop codon, UGA, into selenoproteins in murine EMT6 cells.

90 er by replacing the natural tnaC stop codon, UGA, with UAG or UAA in a tnaC-stop codon-tnaA'-'lacZ re

91 n the construct with the natural stop codon, UGA.

92 incorporated via recoding of the stop codon, UGA.

93 selenocysteine (Sec), encoded by the codon, UGA.

94 ease factor to one of the three stop codons (UGA, UAA or UAG) results in the termination of protein s

95 structure of RF2 in complex with its cognate UGA stop codon in the 70S ribosome.

96 n the four readthrough candidates containing UGA-CUAG, this motif is conserved not only in mammals bu

97 first is a conserved, inefficiently decoded UGA codon in the N-terminal region, which appears to ser

98 ons downstream of this inefficiently decoded UGA which confer the potential for nonsense-mediated dec

99 erine, forms selenocysteyl-tRNA, and decodes UGA.

100 CIS) element, that is necessary for decoding UGA as selenocysteine rather than a stop signal.

101 c) is site-specifically delivered at defined UGA codons in selenoprotein mRNAs.

102 ate and the efficiency of decoding different UGAs.

103 ec incorporation at the first and downstream UGA codons occurs with variable efficiencies to control

104 proximately 10-fold at subsequent downstream UGA codons.

105 he compounding effect of termination at each UGA codon.

106 al and collaborated in Sec insertion at each UGA codon.

107 -nucleotide-long fragments representing each UGA codon context into a luciferase reporter construct h

108 n immediately downstream of the Sec-encoding UGA codon, whereas in eukaryotes a completely different

109 ocated adjacent to a selenocysteine-encoding UGA codon in the eukaryal gene, SEPN1.

110 djacent to, or near, selenocysteine-encoding UGA codons in the Sps2, SelH, SelO, and SelT selenoprote

111 As expected, UGA is the predominant Sec codon in use.

112 We used Bacillus subtilis to express UGA-containing Mycoplasma genes encoding the P30 adhesin

113 ncorporation (i.e., after decoding the first UGA codon as selenocysteine) are fully competent to term

114 Selenocysteine incorporation at the first UGA codon is inefficient but increases by approximately

115 G read-through element upstream of the first UGA codon or by providing a competing messenger RNA in t

116 fic expansion of the genetic code allows for UGA codons to specify the amino acid selenocysteine (Sec

117 he stem (G1922) is specifically critical for UGA codon recognition by the class 1 release factor RF2.

118 appears analogous to cis-acting elements for UGA translation as selenocysteine, although different me

119 itive to antibiotics due to its ten in frame UGA codons.

120 The presence of an in-frame UGA (stop) codon in the coding sequence of selenoprotein

121 15) was identified that contains an in-frame UGA codon and a SECIS element in the 3'-UTR.

122 n the 3'-untranslated region and an in-frame UGA codon are the requisite cis-acting elements for the

123 D helix in ribosomes stalled at the in-frame UGA codon of prfB generates tension on the mRNA that des

124 nic amino acid encoded by a recoded in-frame UGA codon that does not operate as the canonical opal st

125 er polypeptide chain, encoded by an in-frame UGA codon.

126 from Metridium senile that has four in-frame UGA codons and two nearly identical SECIS elements.

127 The in-frame UGA codons are recoded to cotranslationally incorporate

128 s by translational recoding whereby in-frame UGA codons are redefined to encode the selenium containi

129 proximately 31 kDa and contains two in-frame UGA codons presumably encoding selenocysteine.

130 75)Se labeling showed that all four in-frame UGA codons supported Sec insertion and that both SECIS e

131 diated decay due to the presence of in-frame UGA codons that can be decoded as either selenocysteine

132 in vertebrates may contain up to 22 in-frame UGA codons.

133 mdm2 (exon alpha) which includes an in-frame UGA stop codon.

134 teine (Sec), which is encoded by an in-frame UGA stop codon.

135 Multiple in-frame UGAs and two SECIS elements make the mRNA encoding selen

136 G418-mediated suppression of the CFTR G542X UGA mutation.

137 cient stop codon readthrough, and these have UGA immediately followed by CUAG.

138 er protein synthesis levels exhibited higher UGA readthrough, which was confirmed with ribosome-targe

139 ngle cells, and individual cells with higher UGA readthrough grow faster from stationary phase.

140 for the serine 33 and serine 70 residues in UGA decoding in vivo.

141 that support distinct roles for Secisbp2 in UGA-redefinition and mRNA stability.

142 nt loops of this conserved rRNA structure in UGA-dependent translation termination and, taken with pr

143 etic code alterations in ciliates, including UGA --> tryptophan in Blepharisma americanum and the dis

144 c and metabolic features with SR1, including UGA to glycine reassignment and an archaeal-type ribulos

145 ncorporation is able to repress G418-induced UGA readthrough as well as eRF1-induced stimulation of t

146 the C terminus and the adjacent inefficient UGA termination codon act to recruit the SsrA-tagging sy

147 selenoproteins requires recoding of internal UGA stop codons to the 21st non-standard amino acid sele

148 d that the conversion efficiency of PGA into UGA increases in a range of coefficients of dilution unt

149 In mammals, UGA can be reassigned to selenocysteine during translati

150 The phosphoseryl-tRNA and the minor UGA-decoding seryl-tRNA were subsequently identified as

151 odon, which allows decoding of mitochondrial UGA codons as tryptophan.

152 can now decode the predominant mitochondrial UGA tryptophan codons.

153 ynthesis but cannot decode the mitochondrial UGA codons.

154 n codon but can not decode the mitochondrial UGA tryptophan codon.

155 In selenoprotein mRNAs, UGA codons, which typically specify termination, serve a

156 ement, selenoprotein P genes encode multiple UGAs and two SECIS elements.

157 on model that incorporated Sec at non-native UGA codons at rates equal to those of endogenous glutath

158 Due to natural UGA suppression, these Mycoplasma genes were expressed a

159 a minor seryl-tRNA that decoded the nonsense UGA was detected in bovine liver.

160 ptide release at UAA and UAG codons, but not UGA codons.

161 (Eo/Sc eRF1) recognized UAA and UAG, but not UGA, as stop codons.

162 ation of our scheme for the bioproduction of UGA from PGA.

163 ired for efficient translational decoding of UGA and synthesis of selenoproteins.

164 SECIS) elements required for the decoding of UGA as a selenocysteine in the 3'-untranslated region (U

165 The decoding of UGA as Sec requires the reprogramming of translation bec

166 the coding regions immediately downstream of UGA codons.

167 t increase in ribosome density downstream of UGA-Sec codons for a subset of selenoprotein mRNAs and t

168 le effects on ribosome density downstream of UGA-Sec codons that demonstrate gene-specific difference

169 was to systematically examine the effect of UGA codon position on efficiency of Sec insertion.

170 don context in determining the efficiency of UGA readthrough at each of the 10 rat Sel P Sec codons,

171 n initiation in regulating the efficiency of UGA recoding.

172 A striking example of UGA redefinition occurs during translation of the mRNA c

173 eaching an upper limit where the fraction of UGA that is extracted from the bioreactor is maximized.

174 preserve location-dependent dual function of UGA when expressed in mammalian cells.

175 nt termination and is somewhat inhibitory of UGA-dependent termination.

176 elements conducting multiple occurrences of UGA redefinition to control the synthesis of full-length

177 tion RNA structures, the coding potential of UGA codons, and the presence of cysteine-containing homo

178 ant differences, spanning an 8-fold range of UGA readthrough efficiency, were observed, but these dif

179 We suspected that readthrough of UGA by tRNATrp might be the reason for the partial funct

180 letion dramatically decreased readthrough of UGA nonsense mutations caused by G1093A.

181 arkedly enhanced the level of readthrough of UGA-containing Mycoplasma genes.

182 In mammals, the recoding of UGA as Sec depends on the selenocysteine insertion seque

183 Recoding of UGA codons as selenocysteine (Sec) codons in selenoprote

184 Recoding of UGA from a stop codon to selenocysteine poses a dilemma

185 incorporated into proteins via "recoding" of UGA from a stop codon to a sense codon, a process that r

186 oding genes, is essential for recognition of UGA as a codon for Sec rather than as a stop signal.

187 The recognition of UGA as Sec in mammalian selenoproteins requires a Sec in

188 nts that are required for the recognition of UGA as the selenocysteine codon.

189 of selenoprotein messages by redefinition of UGA codons, which normally specify termination of transl

190 ife by dynamic translational redefinition of UGA codons.

191 nslation level by differential regulation of UGA redefinition and Sec incorporation efficiency, altho

192 ss that is characterized by up-regulation of UGA-selenocysteine recoding efficiency and relocalizatio

193 ressed in vivo results in the suppression of UGA nonsense mutations in two reporter genes.

194 A is depolymerized into oligogalacturonates (UGA), which are continuously extracted from the tank.

195 elements resulted in differential effects on UGA readthrough.

196 As that can be separated from its effects on UGA-redefinition.

197 bosomal profiling to determine the impact on UGA recoding in individual selenoproteins.

198 coplasma genes encoding the P30 adhesin (one UGA) of Mycoplasma pneumoniae and methionine sulfoxide r

199 example, Tetrahymena species recognize only UGA as a stop codon, while Euplotes species recognize on

200 Ribosomes encountering premature UAA or UGA codons in the CAN1 mRNA fail to release and, instead

201 any of these are followed with nearby UAA or UGA codons.

202 ding of one of three stop codons UAA, UAG or UGA by the eukaryotic release factor eRF1.

203 iversally conserved stop codons: UAA, UAG or UGA.

204 rmination codons (PTCs), either UAA, UAG, or UGA.

205 Sec or Cys in MsrBs, whereas the three other UGA codons evolved recently and had no homologs with Sec

206 ative selenocysteine decoding of a potential UGA stop codon within the open reading frame.

207 co-translationally inserted at a predefined UGA opal codon by means of Sec-specific translation mach

208 SECIS elements recode UGA codons from "stop" to "sense." These RNA secondary s

209 steine is inserted into proteins by recoding UGA stop codons.

210 t amino acid, encoded by a context-redefined UGA.

211 However, when UAG or UAA replaced UGA, the induced level of expression was also reduced to

212 ntified mutations in Eo/Sc eRF1 that restore UGA recognition and define distinct roles for the TASNIK

213 0% variation between those carrying the same UGA mutation [c.715 C>T; p.(R239*)].

214 ial of the SECIS flanking region and the Sec UGA codon.

215 ementary to the region downstream of the Sec UGA codon.

216 metazoa with highly variable numbers of Sec-UGAs, ranging from a single UGA in certain insects, to 9

217 (6%) translational redefinition of the SEPN1 UGA codon in human cells.

218 The sequence UGA-CUA alone can support 1.5% readthrough, underlying i

219 for Um, and tRNA(Pro(GGG)) for Am. tRNA(Ser(UGA)), previously observed as a TrmJ substrate in Escher

220 tRNAs with A36A37A38, only mt tRNAs tRNA(Ser)UGA and tRNA(Trp)UCA contained detectable i6A37.

221 )UCA level was increased and the mt tRNA(Ser)UGA level was decreased, suggesting that TRIT1 may contr

222 p, only tRNA(Ser)AGA, tRNA(Ser)CGA, tRNA(Ser)UGA, and selenocysteine tRNA with UCA (tRNA([Ser]Sec)UCA

223 f these identity elements into the tRNA(Ser)(UGA) scaffold resulted in phosphorylation of the chimeri

224 terminate at the second, third, and seventh UGA codons.

225 as most selenoprotein mRNAs contain a single UGA codon and a single SECIS element, selenoprotein P ge

226 ertion systems probably decode only a single UGA codon in C.elegans and C.briggsae genomes.

227 e numbers of Sec-UGAs, ranging from a single UGA in certain insects, to 9 in common spider, and up to

228 co-translationally incorporated at specific UGA codons that normally serve as termination signals.

229 (Sec) tRNA (tRNA([Ser]Sec)) decodes specific UGA codons and contains i(6)A.

230 ASec) drives the recoding of highly specific UGA codons from stop signals to Sec.

231 The decoding of specific UGA codons as selenocysteine is specified by the Sec ins

232 rected by translational recoding of specific UGA codons located upstream of a stem-loop structure kno

233 tRNAs, has previously been shown to suppress UGA in vitro in mammals, but not in vivo.

234 ec-tRNA(Sec)) to the ribosome and suppresses UGA codons that are upstream of Sec insertion sequence (

235 However, we found that UGA supported Sec insertion only at its natural position

236 enoenzyme, a cysteine mutant enzyme, and the UGA-terminated protein in mammalian cells and overexpres

237 rders magnitude, and that termination at the UGA codon abolishes activity.

238 the inefficient incorporation of Sec at the UGA codon during mRNA translation augments the nonsense-

239 hate led to targeted insertion of Cys at the UGA codon of thioredoxin reductase 1 (TR1).

240 Although the major readthrough event at the UGA codon was insertion of tryptophan, Sec was also inco

241 chain as compared with selenocysteine at the UGA codon, expression of the catalytically inactive Gpx4

242 ination at UAA and UAG codons but not at the UGA codon.

243 dant enzyme by promoting substitution at the UGA codon.

244 be involved in preventing termination at the UGA/Sec codon.

245 mino acid selenocysteine, as directed by the UGA codon.

246 event must occur since Sec is encoded by the UGA stop codon.

247 e but also directing the PTR by decoding the UGA stop codon as serine.

248 loop RNA structure immediately following the UGA codon and forms part of the coding sequence in bacte

249 noproteins and for ribosome pausing near the UGA-Sec codon in those mRNAs encoding the selenoproteins

250 In eukaryotes, the decoding of the UGA codon as selenocysteine (Sec) requires a Sec inserti

251 t immediately upstream and downstream of the UGA codon significantly affects termination to incorpora

252 stem loop starting six nucleotides 3' of the UGA codon.

253 One of the UGA codons corresponded to the conserved catalytic Sec o

254 s requires the translational recoding of the UGA stop codon as selenocysteine.

255 Trp), thereby permitting the decoding of the UGA stop codon as tryptophan.

256 of C to T seven nucleotides upstream of the UGA stop codon of ssfR was responsible for the phenotype

257 s requires the translational recoding of the UGA stop codon to selenocysteine.

258 elenocysteine (Sec), through recoding of the UGA stop codon, creates a unique class of proteins.

259 For six organisms, the UGA stop codon is translated as tryptophan.

260 y complexes and release factors perturbs the UGA readthrough level.

261 on of selenocysteine (Sec) into protein, the UGA codon is transformed from one that signals translati

262 factor and tRNA(Sec) needed to reassign the UGA codon.

263 y incorporated into proteins by recoding the UGA opal codon with a specialized elongation factor (Sel

264 decoded by the same sequence that spans the UGA stop codon of rabbit beta-globin mRNA were detected.

265 high efficiency appears to require that the UGA be >21 nucleotides from the AUG-start and >204 nucle

266 s, was increased to levels comparable to the UGA at U47.

267 uence element approximately 4.8 kb 3' to the UGA codon in the active center and three short open read

268 a provided that it is spatially close to the UGA codon.

269 to three amino acids that correspond to the UGA stop codon site and/or one or two of the immediate d

270 the approximately 150 nt 3'-adjacent to the UGA, and RNA folding algorithms revealed the potential f

271 a single cytidine residue 3'-adjacent to the UGA.

272 confirmed that in the presence of l-Trp, the UGA stop codon generates higher accumulation of both Tna

273 Unlike Mycoplasma cells, which use the UGA codon for tryptophane, Prochlorococcus uses the stan

274 peroxidase-1 (F-GPX1) expression vector, the UGA at the native position (U47) was mutated to a cystei

275 When the UGA codon was changed to the Trp codon UGG, flagellar as

276 asmic nonsense-mediated decay (NMD) when the UGA selenocysteine (Sec) codon is recognized as nonsense

277 xpression was reduced to 20 and 50% when the UGA stop codon was replaced by UAG or UAA, respectively,

278 by the identity of its stop codon, with the UGA stop codon producing higher expression efficiency of

279 oforms arise from the same mRNA and that the UGAs that specify the second, third, and seventh selenoc

280 on, empowers yeast ribosomes to read-through UGA stop codons.

281 educe l-Trp-dependent expression of the tnaC(UGA) tnaA-lacZ construct and the ability of l-Trp to inh

282 n initiation, structures located adjacent to UGA codons, additional coding sequence regions necessary

283 ique tRNA with an anticodon complementary to UGA, a unique elongation factor specific for this tRNA,

284 trations of translational components lead to UGA readthrough heterogeneity among single cells, which

285 78, and Ser-195 were individually mutated to UGA and transiently expressed in COS-7 cells.

286 ocysteine (Sec) into proteins in response to UGA codons is directed by selenocysteine insertion seque

287 ocysteine (Sec) into proteins in response to UGA codons requires a cis-acting RNA structure, Sec inse

288 is inserted cotranslationally in response to UGA codons within selenoprotein mRNAs in a process requi

289 l insertion of selenocysteine in response to UGA codons.

290 are amino acid selenocysteine in response to UGA stop codons have helped provide a better understandi

291 e sole Trp codon in the sequence (Trp271) to UGA, decreased both the number of flagella and the abili

292 selenoproteins using a unique translational UGA-recoding mechanism.

293 niae and methionine sulfoxide reductase (two UGAs) of Mycoplasma genitalium.

294 ealed downstream of the frameshift site, UCC UGA.

295 A truncated mutant of Int, hInt V371S(UGA), lacking the putative zinc finger could bind DNA wi

296 When UGA decoding is inefficient, as occurs when selenium is

297 d in about 50% inhibition of expression when UGA was replaced by UAG or UAA and the appropriate suppr

298 t is surprisingly frequent in ciliates, with UGA --> tryptophan occurring twice independently.

299 elenoprotein-encoding mRNA and competes with UGA-directed translational termination.

300 side-induced readthrough were observed, with UGA showing greater translational readthrough than UAG o

301 reduced to 15 and 50% of that obtained with UGA as the tnaC stop codon, respectively.