ライフサイエンスコーパス: OMP

1 OMP assembly has been reconstituted in vitro, but assemb

2 OMP binding sites are located primarily in the core doma

3 OMP folding is an essential process in all Gram-negative

4 OMP islands were distributed throughout the cell and con

5 OMPs are assembled into the OM by the beta-barrel assemb

6 OMPs are implicated in the maintenance of cell envelope

7 OMPs are then offloaded to the beta-Barrel Assembly Mach

8 OMPs clustered to form approximately 0.5-mum diameter is

9 OMPs in Gram-negative bacteria rarely have reactive cyst

10 Bioinformatics analysis of >350,000 OMP sequences showed that their length, hydrophobicity a

11 ermined that major outer membrane protein 1 (OMP-19) hypervariable region 1 (HVR1)-specific human mon

12 ve OMPs from the avian strain genome and 107 OMPs from the porcine strain genome with 83% overlap bet

13 stigated the transformation mechanisms of 20 OMPs during the methanogenic step of AD with a focus on

14 and freely available, was developed for 556 OMPs in both positive and negative ionization modes usin

15 tral subunit of the BAM complex, accelerates OMP folding by lowering the kinetic barrier imposed by p

16 In the presence of activating OMP peptides, peptides corresponding to a region of CupB

17 gher cross-reactive immune responses against OMPs isolated from S. Choleraesuis and S. Enteritidis.

18 Moreover, the CupB5 peptide allowed OMP-activated AlgW cleavage of MucA in the presence of t

19 ight suggest the possibility of its being an OMP.

20 -depth characterization of methylation of an OMP at the molecular level and may lead to uncovering th

21 er membrane as well as the TM residues of an OMP determine its functional fold in vivo.

22 sults suggest that the folding process of an OMP is driven by the lipid-facing residues in its hydrop

23 Analysis of an OMP with a domain structure similar to that of LptD, Fhu

24 The TAM also consists of an OMP, designated TamA, and a single inner membrane (IM) p

25 re located primarily in the core domain, and OMP binding results in conformational changes between th

26 A. baumannii infection, but monoclonal anti-OMP antibodies have not been developed, and their potent

27 ction by clinical-grade anti-RSPO3 antibody (OMP-131R10/rosmantuzumab) impairs self-renewal and induc

28 the Wnt pathway with a monoclonal antibody, OMP-18R5.

29 ach is fast, efficient and applicable to any OMP.

30 Using fluorescent colicins as OMP-specific probes, in combination with ensemble and si

31 growth and OM barrier defects, they assemble OMPs with surprising robustness.

32 e challenge that bacteria face in assembling OMPs into the OM is how to overcome the initial energy b

33 We use OMPBioM to assess OMP biogenesis mathematically in a global manner.

34 ctural flexibility between domains assisting OMP recognition, binding and release.

35 aid in the secretion of virulence-associated OMPs.

36 class of dual function, bipartite bacterial OMP.

37 vestigating the folding of several bacterial OMPs using membranes with naturally occurring Escherichi

38 cherichia coli, BamA is the core beta-barrel OMP and, together with four outer membrane lipoproteins,

39 rotein complex consisting of the beta-barrel OMP BamA and lipoproteins BamB, -C, -D, and -E.

40 to this process is the conserved beta-barrel OMP that belongs to the Omp85 superfamily.

41 tion of four putative treponemal beta-barrel OMPs that exhibit the characteristics of multispecific a

42 ent with their classification as beta-barrel OMPs, circular-dichroism spectroscopy revealed the adopt

43 e subjected to degradation, but also because OMPs that assemble slowly can form dominant-negative int

44 ons, we established the mechanism for binary OMP partitioning.

45 Here, we provide evidence that the borrelial OMP P66, a known adhesin with pore-forming activity, for

46 en of the nasal airway was positive for both OMP and the disease-specific isoform of the prion protei

47 d-type SurA inhibits the aggregation of both OMPs, as do the cytoplasmic OMP chaperones trigger facto

48 c antibodies are borreliacidal and that both OMPs are immunogenic during nonhuman primate infection.

49 verall similarity, it is plausible that both OMPs have similar or overlapping functions in this patho

50 chanism for allosteric activation of DegS by OMP-peptide binding.

51 e complex folding environment encountered by OMPs in the periplasm and demonstrate the key role of Sk

52 luences the conformational states sampled by OMPs and thereby affects their recognition by both chape

53 el assembly machinery (BAM), which catalyzes OMP insertion into the outer membrane.

54 ically necessary for the assembly of certain OMPs.

55 e of the beta barrel of the Escherichia coli OMPs OmpLA and EspP creates an energy barrier that imped

56 a mechanism previously reported; conversely, OMP-1-specific huMAb EHRL-4 (IgG3) engaged intracellular

57 tissue specific knock-out mouse by crossing OMP-Cre transgenic mice to Ric-8b floxed mice.

58 regation of both OMPs, as do the cytoplasmic OMP chaperones trigger factor and SecB.

59 the relevance of 11 most frequently detected OMPs for classifying the contamination status of lakes.

60 biological effects associated with detected OMPs that warrant further biomonitoring studies.

61 ust be precisely aligned to ensure efficient OMP insertion.

62 omains of SecDF and YidC, ensuring efficient OMP maturation.

63 acellular loops (ECLs) in LptD, an essential OMP that inserts lipopolysaccharide into the outer membr

64 ole for Skp in the assembly of the essential OMP LptD.

65 ertion in clusters, driving the pre-existing OMP clusters towards cell poles for long-term storage.

66 OMP) deposition and the fate of pre-existing OMPs are still enigmatic despite numerous concerted effo

67 hat antibiotic resistant bacteria expressing OMP TolC could spread more widely within sandy aquifers.

68 parallel chaperone pathways that facilitate OMP assembly.

69 Sixty-five OMPs were confirmed and quantified in samples from 111 l

70 y the high thermodynamic stability of folded OMPs in the OM.

71 imeric protein encapsulates partially folded OMPs, protecting them from the aqueous environment until

72 inery, the previously identified complex for OMP assembly.

73 tide transport-associated (POTRA) domain for OMP reception and assembly.

74 uter membrane-based lipoprotein required for OMP assembly.

75 here the molecular features responsible for OMP targeting to the mycomembrane of Corynebacterium glu

76 eting to the mycomembrane and sufficient for OMP assembly into mycolic acid-containing lipid bilayers

77 lected by CSLAP volunteers were analyzed for OMPs by a suspect screening method based on mixed-mode s

78 To become functional, OMPs must fold and insert into a crowded and asymmetric

79 Here, we use inhibitors of Wnt/Fzd (OMP-18R5/vantictumab) and conditional gene deletion to t

80 TM site sequence analysis from C. glutamicum OMP and other O-acylated proteins in bacteria and eukary

81 e structure-function relationships governing OMPs within native membrane environments remains challen

82 Most Hop and Hom OMPs were susceptible to proteolysis, whereas Hor and Ho

83 model for BamA function, which explains how OMP assembly can be conserved between prokaryotes and eu

84 d this organization lies at the heart of how OMPs are turned over in the membrane.

85 However, OMP biogenesis occurred as a gradient that was highest a

86 In contrast, in OMP knock-out mice, odorant exposure reduced the number

87 ither BamA or BamD causes a global defect in OMP assembly and results in cell death.

88 ogate the role of conformational dynamics in OMP recognition.

89 zymes of the AD process are also involved in OMP biotransformation.

90 amA to the outer membrane and is involved in OMP insertion.

91 Methylation in OMP remains poorly understood.

92 t specificity in this adaptive plasticity in OMP knock-out mice suggests a potential role for this pr

93 that BamD does not play a catalytic role in OMP assembly, but rather functions to regulate the activ

94 bserved may correspond to distinct stages in OMP assembly.

95 artly explained the interlake variability in OMP occurrence.

96 -barrel can serve as a template for incoming OMPs, and the passive model, which claims that a thinned

97 Instead, MRL-494 inhibits OMP biogenesis from outside the OM by targeting BamA.

98 tification of a small molecule that inhibits OMP biogenesis at the cell surface represents a distinct

99 ntigens to human IgG comprised four integral OMPs (PorA, PorB, OpcA and PilQ), a protein which promot

100 relative dominance of responses to integral OMPs in humans emphasizes the importance of this subclas

101 Besides providing insights into OMP biogenesis, our work describes a novel, streamlined

102 Last, OMP also steepens the dose-response relation to improve

103 by utilizing two transgenic reporter lines: OMP-ZsGreen mice which express bright green fluorescent

104 in vitro folding kinetics observed for many OMPs.

105 ermodynamic and kinetic parameters maximizes OMP folding flux and minimizes aggregation and unnecessa

106 target screening of organic micropollutants (OMP) in complex environmental samples is handling of mas

107 Organic micropollutants (OMPs) are pervasive anthropogenic contaminants of receiv

108 approach to monitor organic micropollutants (OMPs) in environmental samples is the combination of tar

109 trations of several organic micropollutants (OMPs) in sewage sludge.

110 pread occurrence of organic micropollutants (OMPs) is a challenge for aquatic ecosystem management, a

111 wever, a Deltaskp mutant displays only minor OMP assembly defects, and no OMPs have been shown to req

112 resulted in the accumulation of misassembled OMPs.

113 complex, on the folding kinetics of a model OMP (tOmpA) using fluorescence spectroscopy, native mass

114 atural substrate orotidine 5'-monophosphate (OMP) for orotidine 5'-monophosphate decarboxylase (OMPDC

115 Moreover, OMP speeds up signal transduction for ORNs to better syn

116 k can also be extended to the synthesis of N-OMP/SiO2 nanocomposites, mesoporous SiO2 , crystalline m

117 itrogen-doped ordered mesoporous polymers (N-OMPs) is developed, which is realized by mixing polymer

118 The synthesized N-OMPs and their derived catalysts are found to exhibit co

119 barrel and promote insertion of the nascent OMP.

120 data from previous reports, however, neither OMP was found to bind human factor H or to be required f

121 regions as the primary entry points for new OMP insertion in clusters, driving the pre-existing OMP

122 splaced to the poles of growing cells as new OMPs take their place.

123 lays only minor OMP assembly defects, and no OMPs have been shown to require Skp for their assembly.

124 cal control over the spontaneously occurring OMP folding reaction in the periplasm.

125 Addition of OMP-1-specific huMAb EHRL-15 (IgG1) prevented infection

126 Hierarchical clustering of OMP occurrence data revealed the relevance of 11 most fr

127 or increasing the spatiotemporal coverage of OMP data sets is through the active involvement of citiz

128 utions on k(cat)/K(m) for decarboxylation of OMP are expressed mainly as an increase in K(m) for the

129 the transition state for decarboxylation of OMP provided by OMPDC represents the sum of 11.8 and 10.

130 the transition state for decarboxylation of OMP, and ca. 8 kcal/mol smaller than for OMPDC-catalyzed

131 (obs) for OMPDC-catalyzed decarboxylation of OMP, and the 4 kcal/mol of binding energy, which is util

132 his research, we investigated the effects of OMP TolC on E. coli transport within saturated sands thr

133 l intrinsic phosphodianion binding energy of OMP is divided between the 8 kcal/mol of binding energy,

134 Lack of OMP increases basal cAMP, thus abolishing differences in

135 ter during folding in vivo Current models of OMP biogenesis in the cellular environment are still in

136 ent to this loop, with the phosphodianion of OMP was probed by determining the kinetic parameters k(c

137 The process of OMP biogenesis has been studied in vivo, and each of its

138 domain architecture and these properties of OMP sequences.

139 The kinetic retardation of OMP folding places a strong negative pressure against sp

140 of citizen volunteers to expand the scale of OMP monitoring.

141 peaks and the corresponding mass spectra of OMP were fully resolved in the presence of highly co-elu

142 In sum, OMPBioM provides a global view of OMP biogenesis that yields unique insights into this ess

143 urce and the high stability and abundance of OMPs.

144 complex catalyzes the efficient assembly of OMPs synthesized de novo in a coupled in vitro transcrip

145 , and closing the gaps in risk assessment of OMPs requires a data-driven approach.

146 aches into the regional impact assessment of OMPs.

147 lex has been implicated in the biogenesis of OMPs.

148 ases and cytochromes, and the degradation of OMPs.

149 gomerization, and conformational dynamics of OMPs in their native OM and intact E. coli.

150 Illustrative examples of OMPs found in environmental samples are presented to hig

151 rm bacteria assist in assembly and export of OMPs.

152 ion, which facilitates the identification of OMPs.

153 ressure against spontaneous incorporation of OMPs into inner bacterial membranes, which would dissipa

154 am complex, which catalyses the insertion of OMPs in the outer membrane.

155 mer that catalyzes the membrane insertion of OMPs.

156 ty of sample matrices and the huge number of OMPs potentially present in samples at low concentration

157 atter presumably drives efficient passage of OMPs.

158 Given its role in the production of OMPs for survival and pathogenesis, BAM represents an at

159 n understanding of the folding properties of OMPs in vitro can help explain the challenges they encou

160 and cytochrome, and gave largest removal of OMPs (removal of 92 +/- 3% for sulfamethoxazole, 84 +/-

161 oducts and to foster the complete removal of OMPs via operational strategies, remain unclear.

162 a sets for target and nontarget screening of OMPs in drinking and wastewater samples, respectively.

163 etermined by the differential stabilities of OMPs in the asymmetrical outer membrane.

164 rkflow enables structure-function studies of OMPs in native cellular environments, provides unexpecte

165 The cumulative effect is to push old OMP islands towards the poles of growing cells, leading

166 e passive and binary in nature, in which old OMPs are displaced to the poles of growing cells as new

167 ; and 4) periodontal disease followed by OM (OMP).

168 Despite extensive studies on OMP biogenesis, it is unclear why OMPs require assembly

169 ), we conducted the first statewide study on OMP occurrence in surface waters of New York lakes.

170 mbly machine (BAM), which is composed of one OMP-BamA-and four lipoproteins-BamB, C, D, and E.

171 This role may be compensated for by other OMP assembly proteins; in the absence of both Skp and Fk

172 Other OMPs, including LamB, are less affected in the Deltaskp

173 icted by promiscuous interactions with other OMPs.

174 .e., two 28-kDa outer membrane proteins (P28/OMP) and a 120-kDa surface protein, were also recognized

175 the membrane, the ability of Skp to prevent OMP aggregation was investigated.

176 for tentative identification of prioritized OMPs.

177 key role of Skp in holding aggregation-prone OMPs prior to their direct or indirect delivery to the m

178 We found that olfactory marker protein (OMP), a protein expressed in mature ORNs, controls both

179 terozygous for the olfactory marker protein (OMP), this adaptive plasticity was strongest in the popu

180 Borrelia burgdorferi outer membrane protein (OMP) BB0406 and found that the gene encoding this OMP wa

181 Outer membrane protein (OMP) biogenesis is critical to bacterial physiology beca

182 ssential beta-barrel outer membrane protein (OMP) biogenesis machinery in Gram-negative bacteria, chl

183 rily for its role in outer membrane protein (OMP) biogenesis, during which the jellyfish-like trimeri

184 plays a key role in outer membrane protein (OMP) biogenesis.

185 The sites of new outer membrane protein (OMP) deposition and the fate of pre-existing OMPs are st

186 The outer membrane protein (OMP) from Neisseria meninigitidis, PorB, is a naturally

187 The outer membrane protein (OMP) TolC is the cell surface component of several drug

188 Two outer membrane protein (OMP) transport systems in diderm bacteria assist in asse

189 on of three putative outer membrane protein (OMP)-encoding genes.

190 alyze methylation of outer membrane protein (OMP).

191 ists in complexes with beta-barrel proteins (OMPs) allowing it to adopt a transmembrane orientation w

192 ntegral outer membrane beta-barrel proteins (OMPs) are assembled by the beta-barrel assembly machine

193 Outer membrane beta-barrel proteins (OMPs) are crucial for numerous cellular processes in pro

194 gion of outer membrane beta-barrel proteins (OMPs) by combining an empirical energy function with a r

195 ophobic beta-barrel Outer-Membrane Proteins (OMPs) - are first secreted across the inner-membrane thr

196 stress, unassembled outer-membrane proteins (OMPs) accumulate in the periplasm and their C-terminal p

197 nces in unassembled outer-membrane proteins (OMPs) activate the AlgW protease, and unassembled lipopo

198 enesis of bacterial outer membrane proteins (OMPs) and has recently been identified as a promising ta

199 d TprI as candidate outer membrane proteins (OMPs) and subsequently demonstrated that TprC is not onl

200 beta-Barrel outer membrane proteins (OMPs) are found in the outer membranes of Gram-negative

201 in the assembly of outer membrane proteins (OMPs) because its absence resulted in the accumulation o

202 lmost all bacterial outer membrane proteins (OMPs) contain a beta barrel domain that serves as a memb

203 Bacterial outer membrane proteins (OMPs) contain a unique "beta barrel" segment that is ins

204 nteractions involve outer membrane proteins (OMPs) expressed on the bacterial surface.

205 ntegral beta-barrel outer membrane proteins (OMPs) function to establish and maintain the selective p

206 antisera targeting outer membrane proteins (OMPs) have shown encouraging results in protecting mice

207 in the assembly of outer membrane proteins (OMPs) in Escherichia coli.

208 Outer membrane proteins (OMPs) in Gram-negative bacteria dictate permeability of

209 The biogenesis of outer-membrane proteins (OMPs) in gram-negative bacteria involves delivery by per

210 esis of beta-barrel outer membrane proteins (OMPs) in Gram-negative bacteria.

211 g and assembling of outer membrane proteins (OMPs) in Gram-negative bacteria.

212 nanometer range for outer-membrane proteins (OMPs) in intact Escherichia coli and native membranes.

213 e used to screen 91 outer membrane proteins (OMPs) incorporated in an antigen microarray panel.

214 tion of beta-barrel outer membrane proteins (OMPs) into the outer membrane of Gram-negative bacteria.

215 containing integral outer membrane proteins (OMPs) into the outer membrane.

216 of the beta-barrel outer membrane proteins (OMPs) is an essential cellular process in Gram-negative

217 of known bacterial outer membrane proteins (OMPs) led to the identification of tp0126 as a gene enco

218 Outer membrane proteins (OMPs) of Pasteurella multocida have various functions re

219 beta-Barrel outer membrane proteins (OMPs) represent the major proteinaceous component of the

220 ogs predicted to be outer membrane proteins (OMPs) revealed that seven have an Msp-like bipartite str

221 (OmpA) are dominant outer membrane proteins (OMPs) that are released by gram-negative bacteria during

222 d chloroplasts have outer membrane proteins (OMPs) that perform many fundamental biological processes

223 ment of beta-barrel outer membrane proteins (OMPs) to enable adaptation to a particular habitat.

224 eract with unfolded outer membrane proteins (OMPs) to promote correct folding and membrane insertion

225 tion of beta-barrel outer membrane proteins (OMPs) to the outer membrane are mediated by the beta-bar

226 predicted to encode outer membrane proteins (OMPs), but there has been relatively little experimental

227 c acids and unusual outer membrane proteins (OMPs), including those with alpha-helical structure.

228 In the case of outer-membrane proteins (OMPs), unfolded-state properties are of particular physi

229 n the biogenesis of outer-membrane proteins (OMPs).

230 -494, that inhibits assembly of OM proteins (OMPs) by the beta-barrel assembly machine (BAM complex).

231 During their biogenesis, OM proteins (OMPs), which function as transporters and receptors, mus

232 atively low density of integral OM proteins (OMPs).

233 were able to confidently predict 98 putative OMPs from the avian strain genome and 107 OMPs from the

234 or other T. pallidum genes encoding putative OMPs/virulence factors and that is often employed as a s

235 s study has increased the number of putative OMPs identified in P. multocida and allowed these OMPs t

236 ly demonstrated that TprC is not only a rare OMP but also forms trimers and has porin activity.

237 ese mutations we demonstrate that these RcsF/OMP complexes are required for sensing OM outer leaflet

238 rmediate common to OMPDC-catalyzed reactions OMP/FOMP and UMP/FUMP.

239 a novel, streamlined method to reconstitute OMP assembly in vitro.

240 t those that relieve the steric clash reduce OMP activation dramatically.

241 Yet no mechanism is known for replacing OMPs in the outer membrane, an issue that is further con

242 this step accounts for much of the reported OMP biotransformation in AD.

243 moting the degradation of six representative OMPs (i.e., sulfamethoxazole, carbamazepine, tylosin, at

244 e mutation bamA (E470K) BamA(E470K) restores OMP biogenesis in the presence of MRL-494.

245 n, for mycomembrane-associated and -secreted OMPs.

246 Our results showed OMP TolC could significantly enhance the transport of E.

247 stochastic methods, we are able to simulate OMP biogenesis under varying genetic conditions, each of

248 Few membrane-spanning OMPs of B. burgdorferi have been definitively identified

249 enhances its chaperone activity for specific OMPs, suggesting one reason for the conservation of mult

250 lateral gate of BamA accelerates spontaneous OMP insertion.

251 least for the assembly of a small 8-stranded OMP in vitro.

252 C-catalyzed reactions of the whole substrate OMP and the substrate pieces (1-beta-D-erythrofuranosyl)

253 the barrel lumen, which indicates substrate OMPs may not be threaded through the barrel during bioge

254 lex then catalyzes the assembly of substrate OMPs and BamA.

255 Our combined results suggest OMP insertion utilizes aspects of both the hybrid barrel

256 e N-terminal domains of protease-susceptible OMPs are exported through an autotransporter pathway.

257 Most of the protease-susceptible OMPs contain a large protease-susceptible extracellular

258 We conclude that OMP plays a key regulatory role in ORN physiology by con

259 Here, we show that OMP peptides initiate a steric clash between the PDZ dom

260 Our results suggest that OMP assembly machineries are required in vivo to enable

261 We observe that OMPs have a prolonged lifetime in the periplasm where an

262 The OMP group had lower BVF and BMD levels compared to the o

263 essential components of this complex are the OMP BamA [which contains a carboxyl-terminal beta-barrel

264 dies are required to refine conclusions, the OMP's chemical structure was a determinant for AK action

265 regulate the conformation of BamA during the OMP assembly reaction.

266 was cotranscribed with the gene encoding the OMP BB0405.

267 fashion compared to other chaperones in the OMP biogenesis network.

268 ession of both cytokines was observed in the OMP group at day 1 (P <0.05).

269 beta and TNF-alpha by IHC was highest in the OMP group at day 1, with progressive reduction thereafte

270 pid environment and the OM in modulating the OMP-folding landscape and discuss the factors that guide

271 The BAM complex consists of the OMP component BamA along with several outer membrane ass

272 us, our findings suggest that opening of the OMP via interaction with the MFP is energy-independent,

273 Skp and SurA, on the folding kinetics of the OMP, PagP.

274 exes without inactivating either RcsF or the OMP.

275 The OMPs in Gram-negative bacteria are inserted and folded i

276 tingly, the in vitro translated forms of the OMPs we analyzed were assembled more rapidly and were ef

277 obial polypeptides were determined for these OMP gene deletion mutants.

278 The ability of these OMP gene deletion mutants to induce immune responses was

279 identified in P. multocida and allowed these OMPs to be identified with a higher degree of confidence

280 Here, we characterize the roles of these OMPs in pathogenesis during bacteremia caused by Klebsie

281 BB0406 and found that the gene encoding this OMP was cotranscribed with the gene encoding the OMP BB0

282 orin and integrin-binding activities of this OMP as they relate to B. burgdorferi physiology and Lyme

283 erol head groups impose a kinetic barrier to OMP folding.

284 de chains stabilize the Michaelis complex to OMP for the decarboxylation reaction, compared with the

285 Here we uncover the process underpinning OMP turnover in E. coli and show it to be passive and bi

286 lifetime in the periplasm where an unfolded OMP makes, on average, hundreds of short-lived interacti

287 x as well as its ability to prevent unfolded OMP (uOMP) aggregation.

288 Together, the results suggest that unfolded OMP substrates bind in a cradle formed between the SurA

289 for entropically favored binding of unfolded OMPs to chaperones and, by facilitating conformational s

290 It has been shown to interact with unfolded OMPs, and the simultaneous loss of Skp and the main peri

291 are disfavored not only because unintegrated OMPs are subjected to degradation, but also because OMPs

292 To bring down this vital OMP-supported barrier to antibiotics, we must first unde

293 To better understand the mechanisms by which OMP precursors were sorted in C. glutamicum, we first in

294 mmon structural features may determine which OMPs require Skp for their assembly.

295 studies on OMP biogenesis, it is unclear why OMPs require assembly machineries to fold into their nat

296 d the conformational changes associated with OMP folding and insertion.

297 ly that BamA and BamD interact directly with OMP substrates.

298 Finally, we targeted the Wnt pathway with OMP-18R5, a therapeutic antibody that interacts with mul

299 ients for the wild-type E. coli strain (with OMP TolC) was usually >50% lower than those of the tolC-

300 s using a wild-type E. coli K12 strain (with OMP TolC), as well as the corresponding transposon mutan