scholarly journals Stochasticity in Protein Levels Drives Colinearity of Gene Order in Metabolic Operons of Escherichia coli

PLoS Biology ◽  
2009 ◽  
Vol 7 (5) ◽  
pp. e1000115 ◽  
Author(s):  
Károly Kovács ◽  
Laurence D. Hurst ◽  
Balázs Papp
Keyword(s):  
Escherichia Coli ◽  
Gene Order ◽  
Protein Levels

scholarly journals Clusters of Charged Residues at the C Terminus of MotA and N Terminus of MotB Are Important for Function of the Escherichia coli Flagellar Motor

2008 ◽  
Vol 190 (15) ◽  
pp. 5517-5521 ◽  
Author(s):  
Edan R. Hosking ◽  
Michael D. Manson
Keyword(s):  
Escherichia Coli ◽  
Flagellar Motor ◽  
Protein Levels ◽  
Partner Protein ◽  
C Terminus ◽  
N Terminus ◽  
Charged Residues ◽  
Positively Charged ◽  
Terminal Cluster

ABSTRACT MotA contains a conserved C-terminal cluster of negatively charged residues, and MotB contains a conserved N-terminal cluster of positively charged residues. Charge-altering mutations affecting these residues impair motility but do not diminish Mot protein levels. The motility defects are reversed by second-site mutations targeting the same or partner protein.

scholarly journals Dexamethasone Suppressed LPS-Induced Matrix Metalloproteinase and Its Effect on Endothelial Glycocalyx Shedding

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Na Cui ◽  
Hao Wang ◽  
Yun Long ◽  
Longxiang Su ◽  
Dawei Liu
Keyword(s):  
Escherichia Coli ◽  
Vascular Endothelium ◽  
Free Water ◽  
Endothelial Glycocalyx ◽  
Sprague Dawley ◽  
Treatment Groups ◽  
Protein Levels ◽  
Sprague Dawley Rats ◽  
The Matrix ◽  
Rat Thoracic Aorta

The aim of this study is to determine the mechanism of sepsis-induced vascular hyperpermeability and the beneficial effect of glucocorticoid in protecting vascular endothelium. Male Sprague-Dawley rats were given either a bolus intraperitoneal injection of a nonlethal dose of LPS (Escherichia coli055:B5, 10 mg/kg, Sigma) or vehicle (pyrogen-free water). Animals of treatment groups were also given either dexamethasone (4 mg/kg, 30 min prior to LPS injection) or the matrix metalloproteinases (MMPs) inhibitor doxycycline (4 mg/kg, 30 min after LPS injection). Both activities and protein levels of MMP-2p<0.001and MMP-9p<0.001were significantly upregulated in aortic homogenates from LPS-treated rats, associated with decreased ZO-1p<0.001and syndecan-1p=0.011protein contents. Both dexamethasone and doxycycline could significantly inhibit MMPs activity and reserve the expressions of ZO-1 and syndecan-1. The inhibition of MMPs by dexamethasone was significantly lower than that by doxycycline, while the rescue of syndecan-1 expression from LPS-induced endotoxemic rat thoracic aorta was significantly higher in the dexamethasone-treated compared to the doxycycline-treatedp=0.03. In conclusion, activation of MMPs plays important role in regulating ZO-1 and syndecan-1 protein levels in LPS mediated endothelial perturbation. Both dexamethasone and doxycycline inhibit activation of MMPs that may contribute to the rescue of ZO-1 and syndecan-1 expression.

scholarly journals OmpC regulation differs between ST131 and non-ST131 Escherichia coli clinical isolates and involves differential expression of the small RNA MicC

2020 ◽  
Vol 75 (5) ◽  
pp. 1151-1158
Author(s):  
Corey S Suelter ◽  
Nancy D Hanson
Keyword(s):  
Escherichia Coli ◽  
Half Life ◽  
Selective Advantage ◽  
Resistance Mechanisms ◽  
Northern Blotting ◽  
Rt Pcr ◽  
E Coli ◽  
Protein Levels ◽  
Porin Proteins ◽  
Mrna Half Life

Abstract Background Virulence genes and the expression of resistance mechanisms undoubtedly play a role in the successful spread of the pandemic clone Escherichia coli ST131. Porin down-regulation is a chromosomal mechanism associated with antibiotic resistance. Translation of porin proteins can be impacted by modifications in mRNA half-life and the interaction among small RNAs (sRNAs), the porin transcript and the sRNA chaperone Hfq. Modifications in the translatability of porin proteins could impact the fitness and therefore the success of E. coli ST131 isolates in the presence of antibiotic. Objectives To identify differences in the translatability of OmpC and OmpF porins for different STs of E. coli by comparing steady-state RNA levels, mRNA half-life, regulatory sRNA expression and protein production. Methods RNA expression was evaluated using real-time RT–PCR and OmpC mRNA half-life by northern blotting. OmpC, OmpF and Hfq protein levels were evaluated by immunoblotting. Results Differences between ST131 and non-ST131 isolates included: (i) the level of OmpC RNA and protein produced with mRNA expression higher for ST131 but OmpC protein levels lower compared with non-ST131 isolates; (ii) OmpC mRNA half-life (21–30 min for ST131 isolates compared with &lt;2–23 min for non-ST131 isolates); and (iii) levels of the sRNA MicC (2- to 120-fold for ST131 isolates compared with −4- to 70-fold for non-ST131 isolates). Conclusions Mechanisms involved in the translatability of porin proteins differed among different STs of E. coli. These differences could provide a selective advantage to ST131 E. coli when confronted with an antibiotic-rich environment.

scholarly journals Impacts of dietary forage and crude protein levels on the shedding of Escherichia coli O157:H7 and Listeria in dairy cattle feces

2016 ◽  
Vol 194 ◽  
pp. 17-22 ◽  
Author(s):  
S. Biswas ◽  
M. Niu ◽  
J.A.D.R.N. Appuhamy ◽  
A.B. Leytem ◽  
R.S. Dungan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Dairy Cattle ◽  
Crude Protein ◽  
Escherichia Coli O157 ◽  
Protein Levels ◽  
Cattle Feces

scholarly journals Rearrangement of Gene Order in thephaCABOperon Leads to Effective Production of Ultrahigh-Molecular-Weight Poly[(R)-3-Hydroxybutyrate] in Genetically Engineered Escherichia coli

2012 ◽  
Vol 78 (9) ◽  
pp. 3177-3184 ◽  
Author(s):  
Ayaka Hiroe ◽  
Kenji Tsuge ◽  
Christopher T. Nomura ◽  
Mitsuhiro Itaya ◽  
Takeharu Tsuge
Keyword(s):  
Escherichia Coli ◽  
Molecular Weight ◽  
Gene Order ◽  
Ralstonia Eutropha ◽  
Genetically Engineered ◽  
Pha Synthase ◽  
Limiting Factor ◽  
Expression Plasmid ◽  
Content Type ◽  
Ultrahigh Molecular Weight

ABSTRACTUltrahigh-molecular-weight poly[(R)-3-hydroxybutyrate] [UHMW-P(3HB)] synthesized by genetically engineeredEscherichia coliis an environmentally friendly bioplastic material which can be processed into strong films or fibers. An operon of three genes (organized asphaCAB) encodes the essential proteins for the production of P(3HB) in the native producer,Ralstonia eutropha. The three genes of thephaCABoperon arephaC, which encodes the polyhydroxyalkanoate (PHA) synthase,phaA, which encodes a 3-ketothiolase, andphaB, which encodes an acetoacetyl coenzyme A (acetoacetyl-CoA) reductase. In this study, the effect of gene order of thephaCABoperon (phaABC,phaACB,phaBAC,phaBCA,phaCAB, andphaCBA) on an expression plasmid in genetically engineeredE. coliwas examined in order to determine the best organization to produce UHMW-P(3HB). The results showed that P(3HB) molecular weights and accumulation levels were both dependent on the order of thephagenes relative to the promoter. The most balanced production result was achieved in the strain harboring thephaBCAexpression plasmid. In addition, analysis of expression levels and activity for P(3HB) biosynthesis enzymes and of P(3HB) molecular weight revealed that the concentration of active PHA synthase had a negative correlation with P(3HB) molecular weight and a positive correlation with cellular P(3HB) content. This result suggests that the level of P(3HB) synthase activity is a limiting factor for producing UHMW-P(3HB) and has a significant impact on P(3HB) production.

scholarly journals Unexpected Stress-Reducing Effect of PhaP, a Poly(3-Hydroxybutyrate) Granule-Associated Protein, in Escherichia coli

2011 ◽  
Vol 77 (18) ◽  
pp. 6622-6629 ◽  
Author(s):  
Alejandra de Almeida ◽  
Mariela V. Catone ◽  
Virgil A. Rhodius ◽  
Carol A. Gross ◽  
M. Julia Pettinari
Keyword(s):  
Escherichia Coli ◽  
Heat Shock ◽  
Stress Proteins ◽  
Protective Role ◽  
Pcr Analysis ◽  
Content Type ◽  
E Coli ◽  
Protein Levels ◽  
Stress Related Genes ◽  
Heat Stress Proteins

ABSTRACTPhasins (PhaP) are proteins normally associated with granules of poly(3-hydroxybutyrate) (PHB), a biodegradable polymer accumulated by many bacteria as a reserve molecule. These proteins enhance growth and polymer production in natural and recombinant PHB producers. It has been shown that the production of PHB causes stress in recombinantEscherichia coli, revealed by an increase in the concentrations of several heat stress proteins. In this work, quantitative reverse transcription (qRT)-PCR analysis was used to study the effect of PHB accumulation, and that of PhaP fromAzotobactersp. strain FA8, on the expression of stress-related genes in PHB-producingE. coli. While PHB accumulation was found to increase the transcription ofdnaKandibpA, the expression of these genes and ofgroES,groEL,rpoH,dps, andyfiDwas reduced, when PhaP was coexpressed, to levels even lower than those detected in the non-PHB-accumulating control. These results demonstrated the protective role of PhaP in PHB-synthesizingE. coliand linked the effects of the protein to the expression of stress-related genes, especiallyibpA. The effect of PhaP was also analyzed in non-PHB-synthesizing strains, showing that expression of this heterologous protein has an unexpected protective effect inE. coli, under both normal and stress conditions, resulting in increased growth and higher resistance to both heat shock and superoxide stress by paraquat. In addition, PhaP expression was shown to reduce RpoH protein levels during heat shock, probably by reducing or titrating the levels of misfolded proteins.

scholarly journals Chromosomal location of a mutation causing chloramphenicol resistance in Escherichia coli K 12

1968 ◽  
Vol 11 (1) ◽  
pp. 97-104 ◽  
Author(s):  
E. C. R. Reeve ◽  
D. R. Suttie
Keyword(s):  
Escherichia Coli ◽  
Gene Order ◽  
Chromosomal Location ◽  
Attachment Site ◽  
Chloramphenicol Resistance ◽  
K 12 ◽  
Resistant Mutation

A chloramphenicol-resistant mutation in Escherichia coli K 12, cmlA1 (previously designated 1a), giving a higher Cm-resistance than other mutations yet examined, has been shown to have a chromosomal location, the gene order being gal, λ, bio, cmlA, pyrD. CmlA can be transduced efficiently into cm-sensitive strains by P1 with little phenotypic lag, and is co-transduced with the λ-attachment site (frequency 1·13%) but not with gal or pyrD.

scholarly journals The Genes Encoding Formamidopyrimidine and MutY DNA Glycosylases in Escherichia coli Are Transcribed as Part of Complex Operons

1999 ◽  
Vol 181 (14) ◽  
pp. 4223-4236 ◽  
Author(s):  
Christine M. Gifford ◽  
Susan S. Wallace
Keyword(s):  
Escherichia Coli ◽  
Gene Order ◽  
Intergenic Region ◽  
Transcription Initiation ◽  
Excision Repair ◽  
Initiation Site ◽  
Dna Glycosylase ◽  
Rnase E ◽  
Coding Region ◽  
Genes Encoding

ABSTRACT Escherichia coli formamidopyrimidine (Fpg) DNA glycosylase and MutY DNA glycosylase are base excision repair proteins that work together to protect cells from the mutagenic effects of the commonly oxidized guanine product 7,8-dihydro-8-oxoguanine. The genes encoding these proteins, fpg and mutY, are both cotranscribed as part of complex operons. fpg is the terminal gene in an operon with the gene order radC,rpmB, rpmG, and fpg. This operon has transcription initiation sites upstream of radC, in theradC coding region, and immediately upstream offpg. There is a strong attenuator in therpmG-fpg intergenic region and three transcription termination sites downstream of fpg. There is an additional site, in the radC-rpmB intergenic region, that corresponds either to a transcription initiation site or to an RNase E or RNase III cleavage site. mutY is the first gene in an operon with the gene order mutY, yggX, mltC, andnupG. This operon has transcription initiation sites upstream of mutY, in the mutY coding region, and immediately upstream of nupG. There also appear to be attenuators in the yggX-mltC and mltC-nupGintergenic regions. The order of genes in these operons has been conserved or partially conserved only in other closely related gram-negative bacteria, although it is not known whether the genes are cotranscribed in these other organisms.

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