ライフサイエンスコーパス: colicin

1 of its similarity to bacterial pore-forming colicins.

2 likely be applicable to many TonB-dependent colicins.

3 is not required for cytotoxicity of group A colicins.

4 sin) and as an attachment site for phage and colicins.

5 sensitive E. coli cells from infection by E colicins.

6 t EHEC and complemented the potency of other colicins.

7 intrinsic to the import mechanism of group A colicins.

8 d for killing by colicin N, but not by other colicins.

9 slocon is distinct from those of other known colicins.

10 e (TA(1-107)) of the translocation domain of colicin A (ColA) and TolB identified the TolB box as a 1

11 nd E1 are structurally homologous to that of colicin A but do not select so remarkably for protons; t

12 this, binding of the disordered T-domain of colicin A causes dramatic conformational changes in TolA

13 t that the colicin channel, particularly the colicin A channel, is selective for protons over other c

14 The interaction of the C-terminal colicin A domain and several chimeric variants with lipi

15 Colicin A forms ion channels in the inner membranes of n

16 The channel formed by colicin A in planar lipid bilayers has an outsized selec

17 ross the membrane, the reversal potential of colicin A is -21 mV, rather than 0.

18 localized to the five C-terminal helices of colicin A.

19 tes transport of the cytotoxic domain of the colicin across the cell envelope.

20 colicin E3 functions in translocation of the colicin across the outer membrane through its interactio

21 protein(s) to form a translocon for passage colicin activity domain.

22 using Escherichia coli populations producing colicins, an antibiotic that kills producer cells' close

23 hypothesized to function like a pore-forming colicin and has been reported to have permeability effec

24 entified as being required for uptake of the colicin and it was presumed to somehow serve as both rec

25 s, those with predicted functions included a colicin and putative proteins involved in transcriptiona

26 the structure may provide insights into how colicins and bacteriophages are able to enter the cell.

27 em is a five-protein assembly parasitized by colicins and bacteriophages that helps stabilize the Gra

28 maintain full OM integrity, and for class A colicins and filamentous phages to enter cells, its prec

29 y wide array of enzymes, including bacterial colicins and homing endonucleases).

30 mplicated in the cellular import pathways of colicins and phages-was measured in vivo.

31 l domain exhibits similarity with DNase-like colicins and pyocins, its role and mechanisms of action,

32 Colicins are a diverse family of large antibacterial pro

33 Channel-forming colicins are bacterial toxins that spontaneously insert

34 The colicins are bacteriocins that target Escherichia coli a

35 Colicins are Escherichia coli-specific bacteriocins that

36 Several colicins are highly effective against key EHEC strains.

37 To prevent host suicide, colicins are inactivated by binding to immunity proteins

38 Colicins are nonantibiotic antimicrobial proteins, produ

39 Colicins are protein antibiotics synthesised by Escheric

40 Colicins are protein toxins produced by Escherichia coli

41 Using fluorescent colicins as OMP-specific probes, in combination with ens

42 nsin, Madison, were on the mode of action of colicins as well as on mRNA and ribosomes.

43 those induced by antimicrobial peptides and colicins, as well as the Bax apoptotic pore.

44 ggests that a function of OmpT is to degrade colicin at the cell surface and thus protect sensitive E

45 his model does not, however, explain how the colicin attains the unfolded conformation necessary for

46 Overall, colicin B adsorption decreased the reactivity of more th

47 epA, either alone or when it interacted with colicin B at 37 degrees C.

48 At 0 degrees C colicin B binding impaired or blocked labelling at 8 of

49 Colicin B caused increased exposure to biotin maleimide

50 concomitant conformational rearrangement of colicin B during its translocation.

51 Colicin B is a 55 kDa dumbbell-shaped protein toxin that

52 s residues from T13 to T51, we conclude that colicin B is translocated through the lumen of FepA, rat

53 However, colicin B penetration into the cell at 37 degrees C did

54 in residues argues against the idea that the colicin B polypeptide traverses the FepA channel.

55 To investigate the mechanism of colicin B translocation across the outer membrane, we en

56 oteins: immobilized TonB-dependent (FepA and colicin B) and TonB-independent (FepADelta3-17, OmpA, an

57 ing and transport of ferric enterobactin and colicins B and D.

58 ColV operon, and pAPEC-O1-ColBM encodes the colicins B and M.

59 Nuclease colicins bind their target receptor in the outer membran

60 domains of the colicin E3 was observed upon colicin binding in vitro to BtuB or OmpF.

61 erface that in E. coli TolA corresponds to a colicin binding site.

62 In contrast to Pal, however, colicin binding to TolB promotes its interaction with ot

63 arge and unusual conformational changes upon colicin binding, opening at the cell surface and positio

64 Structures of colicins bound to OM receptors have been determined and

65 Here we report that the colicin channel, particularly the colicin A channel, is

66 the 'Keio collection' to test sensitivity to colicins (col) A, B, D, E1, E2, E3, E7 and N from groups

67 ing the uptake mechanism of the pore-forming colicin ColIa: How does the TonB box of the colicin cros

68 rgy requirement for the uptake of a nuclease colicin complex and suggest that energy transduced from

69 sed food products and, in the United States, colicins could be approved using the generally recognize

70 Plant-produced colicins could be effectively used for the broad control

71 colicin ColIa: How does the TonB box of the colicin cross the OM following high-affinity binding of

72 rks subsequently accomplish insertion of the colicin cytotoxic domain into or across the IM.

73 epB) have been identified to be required for colicin cytotoxicity in the last 25 years.

74 nent of the machinery hijacked by the tRNase colicin D for its import.

75 ote the association of the central domain of colicin D with the inner membrane before the FtsH-depend

76 ted to the tRNase group of colicins (such as colicin D).

77 of LepB results in a stable interaction with colicin D, with a stoichiometry of 1:1 and a nanomolar K

78 ion, and inactivation of arginine tRNAs with colicin D.

79 a single column chromatography step without colicin denaturation.

80 The interaction between colicin DNase domains and their inhibitory immunity (Im)

81 The colicin DNase-Im interaction is a model system for the s

82 Our study highlights how colicin DNases are able to utilise both conserved and va

83 the energetics of Im protein recognition by colicin DNases through a combination of E9 DNase alanine

84 Data suggest a two-receptor model for colicin E1 (ColE1) translocation across the outer membra

85 unter-selection escape by 425-fold, compared colicin E1 alone.

86 urrent and the conformational flexibility of colicin E1 channel domain depend on the membrane surface

87 urther support for the umbrella model of the colicin E1 channel domain.

88 f the loops were essential for the action of colicin E1 or E3, which is consistent with the crystallo

89 but counter-selection escape frequency using colicin E1 precludes using tolC for inefficient genetic

90 (Val(447)-Gly(475) and Ile(508)-Ile(522)) of colicin E1 was investigated by a site-directed fluoresce

91 ile its absence renders the cell tolerant to colicin E1.

92 bility of cobalamin to inhibit the action of colicin E1.

93 n complex between the endonuclease domain of colicin E2 and its cognate immunity (Im) protein, Im2 (K

94 Arg(452) at the R/C-domain interface in colicin E2 was found have an essential role at a putativ

95 s was that the bound coiled-coil R-domain of colicin E2, compared with that of colicin E3, was extend

96 due coiled-coil receptor-binding R-domain of colicin E3 (E3R135) suggested a novel mechanism for impo

97 3 residue glycine-rich N-terminal segment of colicin E3 (T83) that occludes OmpF ion channels yielded

98 x of BtuB and the receptor binding domain of colicin E3 forms a basis for further analysis of the mec

99 t-defective protein, or by the addition of a Colicin E3 fragment, which stabilizes the Ton box in a f

100 The 315-residue N-terminal T domain of colicin E3 functions in translocation of the colicin acr

101 Cellular import of colicin E3 is initiated by high affinity binding of the

102 Colicin E3 molecules of sufficient length display normal

103 th the crystallographic observation that the colicin E3 receptor-binding domain can contact almost al

104 constitution of Imm in a complex with C96 or colicin E3 restored the native structure.

105 within the hydrophobic core of the isolated colicin E3 rRNase domain causes the enzyme to become an

106 by inducing one partner of the high-affinity colicin E3 rRNase domain-Im3 complex (K(d) approximately

107 fer the C-terminal cytotoxic domain (C96) of colicin E3 through the Escherichia coli outer membrane.

108 e translocation and cytotoxic domains of the colicin E3 was observed upon colicin binding in vitro to

109 mplex, the colicin translocon, consisting of colicin E3, BtuB and OmpF.

110 domain of colicin Ia is replaced by that of colicin E3, this chimera effectively kills cells, provid

111 -domain of colicin E2, compared with that of colicin E3, was extended by two and five residues at the

112 lease-fold, and RNases of the EndoU-like and colicin E3-like cytotoxic RNases-folds.

113 llular import of colicins such as the rRNase colicin E3.

114 s bound tightly in a complex with the folded colicin E3.

115 ted to the rRNase group of colicins (such as colicin E4), while klebicin D is most closely related to

116 Im5 in a complex with the activity domain of colicin E5 (E5-CRD) at 1.15A resolution.

117 Cells that produce colicin E5 also synthesize the cognate immunity protein

118 nterface account for specific recognition of colicin E5 by Im5.

119 Colicin E5 is a tRNA-specific ribonuclease that recogniz

120 Colicin E5 specifically cleaves four tRNAs in Escherichi

121 hibition by physically blocking the cleft in colicin E5 that engages the RNA substrate.

122 m5) that rapidly and tightly associates with colicin E5 to prevent it from cleaving its own tRNAs to

123 RNase T1, colicin E5, and mazF were applied in parallel to provide

124 ional study, allows us to propose a model of colicin E5-tRNA interactions, suggesting the molecular b

125 cular residues in recognition and binding of colicin E5.

126 nition and the mechanism of tRNA cleavage by colicin E5.

127 Here we have used the nuclease domain of colicin E7 (N-ColE7) from Escherichia coli in complex wi

128 ately 10(-14)-10(-17) M) complex between the Colicin E7 DNase (CE7) and its inhibitor, Immunity prote

129 ineered a modest specificity switch into the colicin E7 DNase-Im7 immunity protein complex by identif

130 rotein L9 (CTL9), FKBP12, alpha-lactalbumin, colicin E7 immunity protein 7 (IM7), colicin E9 immunity

131 with an application to the four-helix bundle colicin E7 immunity protein, Im7, which folds via a part

132 sible on-pathway folding intermediate of the colicin E7 immunity protein.

133 A mixture of colicin M and colicin E7 showed very high activity against all major E

134 elical protein Im7 (an inhibitor protein for colicin E7 that provides immunity to cells producing col

135 E7 that provides immunity to cells producing colicin E7) folds via a three-state mechanism involving

136 cognate partner for Im7, the DNase domain of colicin E7, causes the dynamic processes associated with

137 y to surface residues involved in binding to colicin E7, showing how the evolutionary pressures that

138 mechanism of inhibition seen with the DNase colicins E7/E9 and from other nuclease-inhibitor complex

139 Antibacterial nuclease colicins such as colicin E9 (ColE9) also bind the beta-propeller domain o

140 We have studied how the bacteriocin colicin E9 (ColE9) assembles a cytotoxic translocon at t

141 omparison of this structure with that of the colicin E9 (ColE9) TolB box-TolB complex, together with

142 m of the dissociation of the DNase domain of colicin E9 (E9) and immunity protein 9 (Im9) complex usi

143 lbumin, colicin E7 immunity protein 7 (IM7), colicin E9 immunity protein 9 (IM9), spectrin R17 domain

144 d that the amino-terminal 80 residues of the colicin E9 molecule, which is the region that interacts

145 sm and time required for the DNase domain of colicin E9 to reach the cytoplasm.

146 eminiscent of that observed for the nuclease colicin E9.

147 xic endonuclease domain from bacterial toxin colicin (E9) in complex with its cognate immunity protei

148 nts using meats spiked with E. coli O157:H7, colicins efficiently reduced the population of the patho

149 Colicin endonucleases (DNases) are bound and inactivated

150 Among the colicins examined, plant-expressed colicin M had the bro

151 Some of the bactericidal proteins known as colicins exert their toxic action by forming a large, no

152 Hence, colicin expressers may be engaged in risk-reducing strat

153 tion of elongated, slow-growing cells formed colicin-expressing hotspots, placing a significant burde

154 Here we demonstrate very high levels of colicin expression (up to 3 g/kg of fresh biomass) in to

155 Colicin expression is a costly trait, and it has been pr

156 namic, subpopulations: the majority silenced colicin expression, while a small fraction of elongated,

157 Antibacterial toxins of the colicin family, which could provide new antibiotic funct

158 this interaction has only been studied using colicins from Escherichia coli.

159 ifically, adding a DNA-damaging toxin (DNase colicin) from another strain induced mass cell suicide w

160 rientation of the R-domain of the nuclease E colicins has a function in the recruitment of another me

161 r E. coli using protein antibiotics known as colicins has been known for many years, but the mechanis

162 Colicins have evolved to use both transporters and other

163 To accomplish cellular import, colicins have parasitized E. coli nutrient transporters

164 Unlike the non-specific H-N-H colicins, however; substitution of the conserved asparag

165 o a specific receptor in the outer membrane, colicin I receptor (70 kDa), and subsequently translocat

166 We determined crystal structures of colicin I receptor alone and in complex with the recepto

167 data using full-length colicin Ia show that colicin I receptor is necessary for cell surface binding

168 With Cir, addition of colicin Ia (the microbial toxin that targets Cir) to the

169 he receptor participates in translocation of colicin Ia across the outer membrane.

170 Regions of both colicin Ia and diphtheria toxin N-terminal to the channe

171 uggests that the membrane-bound structure of colicin Ia channel domain may be described as a "molten

172 Colicin Ia channel domain was reconstituted into membran

173 and segmental motion of the closed state of colicin Ia channel-forming domain in membranes of differ

174 d positioning the receptor binding domain of colicin Ia directly above it.

175 Colicin Ia is a 69 kDa protein that kills susceptible Es

176 show that if the receptor-binding domain of colicin Ia is replaced by that of colicin E3, this chime

177 Functional data using full-length colicin Ia show that colicin I receptor is necessary for

178 We modelled the interaction with full-length colicin Ia to show that the channel forming domain is in

179 Deletion of colicin Ia's receptor-binding domain results in a protei

180 Thus, in addition to binding to colicin Ia's receptor-binding domain, Cir also binds wea

181 Colicin Ia, a channel-forming bactericidal protein, uses

182 from other Gram-negative pathogens, notably, colicin Ia.

183 complex with the receptor binding domain of colicin Ia.

184 cated than does the translocation pathway of colicin Ia.

185 ted by that toxin but is not translocated by colicin Ia.

186 ound states of the channel-forming domain of colicin Ia.

187 The 10-helix channel-forming domains of colicins Ia and E1 are structurally homologous to that o

188 The colicin immunity protein Im7 folds from its unfolded sta

189 Here we make progress by studying the colicin immunity protein Im9.

190 the observation that specificity contacts in colicin-immunity protein complexes can involve different

191 partite complex affinity, whereby the stable colicin:immunity protein complex required for host prote

192 ein is essential for cytotoxicity of group A colicins, implying that TolQRA provides the sole pathway

193 into the OmpF porin, a translocon model for colicin import has been inferred.

194 sis for further analysis of the mechanism of colicin import through the bacterial outer membrane.

195 embrane in a fixed orientation that triggers colicin import.

196 translocation is clearly distinct from known colicin-import pathways because DeltatolA DeltatonB targ

197 tant requirement for rapid inhibition of the colicin in the producing bacterial cell.

198 ColN is, currently, unique among colicins in requiring LPS and, combined with previous da

199 Colicin N is unique among known colicins in that only OmpF had been identified as being

200 Unexpectedly, TonB was also required for colicin-induced exposure of the FepA TonB box, suggestin

201 ty, without affecting TolC-mediated phage or colicin infection.

202 Most colicins initially bind to an outer membrane protein rec

203 , allowing an understanding of how these two colicins interact in a different way with a common trans

204 The colicin interactions with BtuB and OmpF have a major ele

205 munity protein release is a pre-requisite of colicin intoxication, which occurs on a timescale of min

206 ug domain in either structure, implying that colicin is not imported through the outer membrane by Bt

207 anslocon for cellular import of the nuclease colicins is a demonstrably dynamic process, because it d

208 ceptor, complexed to fluorescent antibody or colicin, is 0.05+/-0.01 mum2/s and 0.10+/-0.02 mum2/s, r

209 ion, either before or after induction of the colicin K gene promoter.

210 d by investigating the proteins bound to the colicin K gene regulatory region, either before or after

211 The colicin-LepB interaction is shown to require only a shor

212 The colicin-like bacteriocins are potent protein antibiotics

213 wever, despite the fact that closely related colicin-like bacteriocins are widely produced by Gram-ne

214 Colicin-like bacteriocins show potential as next generat

215 Unlike classical colicin-like nuclease toxins, the overwhelming majority

216 entified the conserved LepB binding motif in colicin-like ORFs from 13 additional bacterial species.

217 Colicin M (ColM) is the only enzymatic colicin reported

218 A mixture of colicin M and colicin E7 showed very high activity again

219 Among the colicins examined, plant-expressed colicin M had the broadest antimicrobial activity agains

220 arison of the structures of syringacin M and colicin M reveals that, in addition to the expected simi

221 We have structurally characterized the colicin M-like bacteriocin, pectocin M2, which is active

222 we present the structure and function of the colicin M-like bacteriocin, syringacin M from Pseudomona

223 To test the bet-hedging strategy in colicin-mediated interactions, competitions between coli

224 have suggested that the pore-forming group A colicin N (ColN) instead uses lipopolysaccharide as a re

225 ecently, genetic screens have suggested that colicin N (ColN), which has no high-affinity receptor, t

226 e conformational behavior of the T-domain of colicin N (ColN-T) to understand why such domains are wi

227 The fact that both colicin N and filamentous phage exploit TolAIII in a sim

228 al. show that the receptor-binding domain of colicin N binds to LPS, and does not require OmpF for th

229 al time, that OmpF mediates the insertion of colicin N into lipid monolayers.

230 Colicin N is a pore-forming bacteriocin that enters targ

231 90-residue unstructured N-terminal domain of colicin N is cytotoxic.

232 Colicin N is unique among known colicins in that only Om

233 y interacting with other domains of the same colicin N molecule and later, during cell killing, bindi

234 We have found that the colicin N T-domain-TolAIII interaction is strikingly sim

235 This revealed that colicin N unfolds and binds to the OmpF-lipid interface.

236 scattering to investigate the interaction of colicin N with its outer membrane receptor protein OmpF.

237 The positions of lipids, colicin N, and OmpF were separately resolved within comp

238 ynthesis as uniquely required for killing by colicin N, but not by other colicins.

239 For colicin N, the receptor-binding domain does not recogniz

240 fined the three-dimensional structure of the colicin N-OmpF complex.

241 proteins (OmpF and TolA) used by full-length colicin N.

242 teral association of OmpF in the presence of colicin N.

243 e a significant association between nuclease colicins, NBs specific for Escherichia coli, and virulen

244 ogether with genetic analysis and studies on colicin occlusion of OmpF channels, this implied a colic

245 that they encode the production of different colicins; pAPEC-O2-ColV contains an intact ColV operon,

246 Involvement of OmpF in colicin passage through the OM was further documented by

247 Treatments with low (less than 10 mg colicins per L) concentrations reduced the pathogenic ba

248 These blooms boosted conjugative HGT of the colicin-plasmid p2 from Salmonella enterica serovar Typh

249 een a chlamydial ORFan protein and bacterial colicin pore-forming domain.

250 Colicins, produced by and toxic to Escherichia coli bact

251 ting fluorescently labelled Escherichia coli colicin producers with non-producing resistant and sensi

252 s-or bet-hedging-as they balance the cost of colicin production with the need to repel competitors.

253 an OFF switch for the Tol assembly, whereas colicins promote an ON state even though mimicking Pal.

254 The mechanisms by which colicins, protein toxins produced by Escherichia coli, k

255 5) suggested a novel mechanism for import of colicin proteins across the outer membrane.

256 stals of the apo form of the vitamin B12 and colicin receptor, BtuB, that diffract to 1.95 A have bee

257 ffusion coefficient (D) of BtuB, the primary colicin receptor, complexed to fluorescent antibody or c

258 is initiated by high affinity binding of the colicin receptor-binding (R) domain to the vitamin B(12)

259 Colicin M (ColM) is the only enzymatic colicin reported to date that inhibits cell wall peptido

260 To achieve this, most colicins require an abundant porin (e.g. OmpF) plus a lo

261 study, it was found that cytotoxicity of the colicin requires a minimum length of 19 to 23 residues b

262 tructure was sought of OmpF with an inserted colicin segment.

263 odel is the requirement for unfolding of the colicin segments inserted into OmpF.

264 -mediated interactions, competitions between colicin-sensitive and producer cells were simulated usin

265 ific sRNA Esr41, which was shown to regulate colicin sensitivity and iron transport in E. coli Numero

266 To better understand the dependence of colicin structure and dynamics on the membrane surface p

267 have detailed mechanistic information on how colicins subvert the periplasmic complexes of TolQRAB/Pa

268 cherichia coli and that this is subverted by colicins such as ColE9 to initiate their OM translocatio

269 Antibacterial nuclease colicins such as colicin E9 (ColE9) also bind the beta-p

270 ion of the translocon for cellular import of colicins such as the rRNase colicin E3.

271 most closely related to the tRNase group of colicins (such as colicin D).

272 most closely related to the rRNase group of colicins (such as colicin E4), while klebicin D is most

273 Group A colicins, such as ColA, parasitize the Tol network throu

274 has ever been identified for TonB-dependent colicins, such as Ia.

275 or the first time the dynamic structure of a colicin T-domain.

276 The N-terminal domain of the colicin that carries the TolA-binding epitope, the trans

277 n an early translocation event, allowing the colicin to bind to the TolB protein in the periplasm.

278 Therefore, another pathway is needed for the colicin to cross the outer membrane, but no 'second rece

279 Extended receptor-binding domains allow some colicins to search by lateral diffusion for binding site

280 ), which have not been observed in any other colicin-Tol protein complex.

281 mf is also critical for the translocation of colicin toxins, which exploit the energized Ton and Tol

282 systems, which are exploited to internalize colicin toxins.

283 The implications of this unfolding step for colicin translocation across membranes are discussed.

284 n occlusion of OmpF channels, this implied a colicin translocon consisting of BtuB and OmpF that woul

285 d by immuno-extraction of an OM complex, the colicin translocon, consisting of colicin E3, BtuB and O

286 reporter system for monitoring DNA damage in colicin-treated cells and illustrate the value of this r

287 Group A colicins typically parasitize the proton-motive force-li

288 It is concluded that free energy for colicin unfolding is provided by binding of the R- domai

289 FRET analysis was employed to study colicin unfolding upon interaction with BtuB and OmpF.

290 Nuclease colicins use members of the tol operon for their translo

291 Many colicins use the outer membrane porin, OmpF, as that tra

292 also became more resistant to bile salts and colicin V and grew 50% slower in vitro in mucus and 15%

293 toplasmic membrane protein CvaB, involved in colicin V secretion in Escherichia coli, belongs to the

294 rane protein TolC constitute the bacteriocin colicin V secretion system in Escherichia coli.

295 55 mot-1 is more resistant to bile salts and colicin V than E. coli MG1655 DeltaflhD and grows ca. 15

296 the role of the CvaB CTD in the secretion of colicin V, a truncated construct of this domain was made

297 coli that do not perform lysis to the DNase colicin, we found that mass lysis occurs when cells are

298 Im helix III is strictly conserved in colicins where an Asp forms polar interactions with the

299 required for the cytotoxic action of group A colicins, which are proposed to insert their translocati

300 Interaction of the TolB box of Group A colicins with the TolB protein in the periplasm of Esche