Expression of theEscherichia colichromosomalarsoperon

1996 ◽  
Vol 42 (7) ◽  
pp. 662-671 ◽  
Author(s):  
Jie Cai ◽  
Michael S. DuBow
Keyword(s):  
Escherichia Coli ◽  
Northern Blotting ◽  
Open Reading Frames ◽  
Gene Fusions ◽  
Arsenic Resistance ◽  
E Coli ◽  
Ars Operon ◽  
Arsenic Detoxification ◽  
Transcriptional Fusions ◽  
Reading Frames

A chromosomally located operon (ars) of Escherichia coli has been previously shown to be functional in arsenic detoxification. DNA sequencing revealed three open reading frames homologous to the arsR, arsB, and arsC open reading frames of plasmid-based arsenic resistance operons isolated from both E. coli and staphylococcal species. To examine the outline of transcriptional regulation of the chromosomal ars operon, several transcriptional fusions, using the luciferase-encoding luxAB genes of Vibrio harveyi, were constructed. Measurement of the expression of these gene fusions demonstrated that the operon was rapidly induced by sodium arsenite and negatively regulated by the trans-acting arsR gene product. Northern blotting and primer extension analyses revealed that the chromosomal ars operon is most likely transcribed as a single mRNA of approximately 2100 nucleotides in length and processed into two smaller mRNA products in a manner similar to that found in the E. coli R773 plasmid-borne ars operon. However, transcription was found to initiate at a position that is relatively further upstream of the initiation codon of the arsR coding sequence than that determined for the E. coli R773 plasmid's ars operon.Key words: arsenic resistance, Escherichia coli, transcription, gene fusions.

scholarly journals Genome Sequence of a T4-like Phage, Escherichia Phage vB_EcoM-Sa45lw, Infecting Shiga Toxin-Producing Escherichia coli Strains

2019 ◽  
Vol 8 (32) ◽  
Author(s):  
Yen-Te Liao ◽  
Yujie Zhang ◽  
Alexandra Salvador ◽  
Vivian C. H. Wu
Keyword(s):  
Escherichia Coli ◽  
Surface Water ◽  
Genome Size ◽  
Shiga Toxin ◽  
Open Reading Frames ◽  
Content Type ◽  
E Coli ◽  
Double Stranded Dna ◽  
A Genome ◽  
Reading Frames

Escherichia phage vB_EcoM-Sa45lw, a new member of the T4-like phages, was isolated from surface water in a produce-growing area. The phage, containing double-stranded DNA with a genome size of 167,353 bp and 282 predicted open reading frames (ORFs), is able to infect generic Escherichia coli and Shiga toxin-producing E. coli O45 and O157 strains.

scholarly journals A Stress-Induced Bias in the Reading of the Genetic Code in Escherichia coli

mBio ◽  
2016 ◽  
Vol 7 (6) ◽  
Author(s):  
Adi Oron-Gottesman ◽  
Martina Sauert ◽  
Isabella Moll ◽  
Hanna Engelberg-Kulka
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Ribosomal Protein ◽  
Genetic Code ◽  
Open Reading Frames ◽  
Translation Machinery ◽  
E Coli ◽  
Universal Characteristic ◽  
Living Organisms ◽  
Reading Frames

ABSTRACT Escherichia coli mazEF is an extensively studied stress-induced toxin-antitoxin (TA) system. The toxin MazF is an endoribonuclease that cleaves RNAs at ACA sites. Thereby, under stress, the induced MazF generates a stress-induced translation machinery (STM), composed of MazF-processed mRNAs and selective ribosomes that specifically translate the processed mRNAs. Here, we further characterized the STM system, finding that MazF cleaves only ACA sites located in the open reading frames of processed mRNAs, while out-of-frame ACAs are resistant. This in-frame ACA cleavage of MazF seems to depend on MazF binding to an extracellular-death-factor (EDF)-like element in ribosomal protein bS1 (bacterial S1), apparently causing MazF to be part of STM ribosomes. Furthermore, due to the in-frame MazF cleavage of ACAs under stress, a bias occurs in the reading of the genetic code causing the amino acid threonine to be encoded only by its synonym codon ACC, ACU, or ACG, instead of by ACA. IMPORTANCE The genetic code is a universal characteristic of all living organisms. It defines the set of rules by which nucleotide triplets specify which amino acid will be incorporated into a protein. Our results represent the first existing report on a stress-induced bias in the reading of the genetic code. We found that in E. coli , under stress, the amino acid threonine is encoded only by its synonym codon ACC, ACU, or ACG, instead of by ACA. This is because under stress, MazF generates a stress-induced translation machinery (STM) in which MazF cleaves in-frame ACA sites of the processed mRNAs.

scholarly journals Cloning, sequencing and expression in Escherichia coli of the rubredoxin gene from Clostridium pasteurianum

1992 ◽  
Vol 285 (1) ◽  
pp. 255-262 ◽  
Author(s):  
I Mathieu ◽  
J Meyer ◽  
J M Moulis
Keyword(s):  
Escherichia Coli ◽  
Protein Sequence ◽  
Coli Strain ◽  
Open Reading Frames ◽  
Transcriptional Unit ◽  
Clostridium Pasteurianum ◽  
Visible Absorption ◽  
E Coli ◽  
Sequencing And Expression ◽  
Reading Frames

A 3.9 kb BglII-HindIII DNA fragment containing the rubredoxin gene from Clostridium pasteurianum has been cloned using oligonucleotide probes designed from the protein sequence. The 2675 bp SspI-HindIII portion of this fragment has been sequenced and found to contain three open reading frames in addition to the rubredoxin gene. The putative product of one of these open reading frames is similar to various thioredoxin reductases. The rubredoxin gene translates into a sequence that differs from the previously published protein sequence in three positions, D-14, D-22 and E-48 being replaced by the corresponding amides. These changes have been confirmed by partial resequencing of the protein. Promoter-like sequences and a transcription termination signal have been found near the sequence of the rubredoxin gene, which may therefore constitute an independent transcriptional unit. Expression of C. pasteurianum rubredoxin in Escherichia coli strain JM109 has been optimized by subcloning a 476 bp SspI-SspI fragment encompassing the rubredoxin gene. Under these conditions, the latter gene was partly under the control of the lac promoter of pUC18, and the level of rubredoxin production could be increased twofold on addition of a lactose analogue, thus reaching 2-3 mg of pure protein/l of culture. Recombinant rubredoxin was produced in E. coli cells as the holoprotein, and displayed a u.v.-visible-absorption spectrum identical with that of the rubredoxin purified from C. pasteurianum. M.s. and N-terminal sequencing showed that C. pasteurianum rubredoxin expressed in E. coli differs from its native counterpart by having an unblocked N-terminal methionine.

scholarly journals A Novel Pathogenicity Island Integrated Adjacent to the thrW tRNA Gene of Avian Pathogenic Escherichia coli Encodes a Vacuolating Autotransporter Toxin

2003 ◽  
Vol 71 (9) ◽  
pp. 5087-5096 ◽  
Author(s):  
V. R. Parreira ◽  
C. L. Gyles
Keyword(s):  
Escherichia Coli ◽  
Serine Protease ◽  
Trna Gene ◽  
Signal Sequence ◽  
Sequence Similarity ◽  
Pathogenicity Island ◽  
Open Reading Frames ◽  
Integrase Gene ◽  
E Coli ◽  
Reading Frames

ABSTRACT We report the complete nucleotide sequence and genetic organization of the Vat-encoding pathogenicity island (PAI) of avian pathogenic Escherichia coli strain Ec222. The 22,139-bp PAI is situated adjacent to the 3′ terminus of the thrW tRNA gene, has a G+C content of 41.2%, and includes a bacteriophage SfII integrase gene, mobile genetic elements, two open reading frames with products exhibiting sequence similarity to known proteins, and several other open reading frames of unknown function. The PAI encodes an autotransporter protein, Vat (vacuolating autotransporter toxin), which induces the formation of intracellular vacuoles resulting in cytotoxic effects similar to those caused by the VacA toxin from Helicobacter pylori. The predicted 148.3-kDa protein product possesses the three domains that are typical of serine protease autotransporters of Enterobacteriaceae: an N-terminal signal sequence of 55 amino acids, a 111.8-kDa passenger domain containing a modified serine protease site (ATSGSG), and a C-terminal outer membrane translocator of 30.5 kDa. Vat has 75% protein homology with the hemagglutinin Tsh, an autotransporter of avian pathogenic E. coli. A vat deletion mutant of Ec222 showed no virulence in respiratory and cellulitis infection models of disease in broiler chickens. We conclude that the newly described PAI and Vat may be involved in the pathogenicity of avian septicemic E. coli strain Ec222 and other avian pathogenic E. coli strains.

scholarly journals The Iron- and Temperature-RegulatedcjrBC Genes of Shigella and Enteroinvasive Escherichia coli Strains Code for Colicin Js Uptake

2001 ◽  
Vol 183 (13) ◽  
pp. 3958-3966 ◽  
Author(s):  
David Šmajs ◽  
George M. Weinstock
Keyword(s):  
Escherichia Coli ◽  
Open Reading Frames ◽  
Cosmid Library ◽  
E Coli ◽  
Order Of Magnitude ◽  
Fur Protein ◽  
The Difference ◽  
K 12 ◽  
Reading Frames ◽  
Made In

ABSTRACT A cosmid library of DNA from colicin Js-sensitive enteroinvasiveEscherichia coli (EIEC) strain O164 was made in colicin Js-resistant strain E. coli VCS257, and colicin Js-sensitive clones were identified. Sensitivity to colicin Js was associated with the carriage of a three-gene operon upstream of and partially overlapping senB. The open reading frames were designated cjrABC (for colicin Js receptor), coding for proteins of 291, 258, and 753 amino acids, respectively. Tn7 insertions in any of them led to complete resistance to colicin Js. A near-consensus Fur box was found upstream ofcjrA, suggesting regulation of the cjroperon by iron levels. CjrA protein was homologous to iron-regulatedPseudomonas aeruginosa protein PhuW, whose function is unknown; CjrB was homologous to the TonB protein fromPseudomonas putida; and CjrC was homologous to a putative outer membrane siderophore receptor from Campylobacter jejuni. Cloning experiments showed that the cjrBand cjrC genes are sufficient for colicin Js sensitivity. Uptake of colicin Js into sensitive bacteria was dependent on the ExbB protein but not on the E. coli K-12 TonB and TolA, -B, and -Q proteins. Sensitivity to colicin Js is positively regulated by temperature via the VirB protein and negatively controlled by the iron source through the Fur protein. Among EIEC strains, two types of colicin Js-sensitive phenotypes were identified that differed in sensitivity to colicin Js by 1 order of magnitude. The difference in sensitivity to colicin Js is not due to differences between the sequences of the CjrB and CjrC proteins.

scholarly journals Cloning and Expression of clt Genes Encoding Milk-Clotting Proteases from Myxococcus xanthus 422

2004 ◽  
Vol 70 (10) ◽  
pp. 6337-6341 ◽  
Author(s):  
M. Poza ◽  
M. Prieto-Alcedo ◽  
C. Sieiro ◽  
T. G. Villa
Keyword(s):  
Escherichia Coli ◽  
Myxococcus Xanthus ◽  
Open Reading Frames ◽  
Cloning And Expression ◽  
Gene Library ◽  
Expression Systems ◽  
E Coli ◽  
Milk Clotting ◽  
Genes Encoding ◽  
Reading Frames

ABSTRACT The screening of a gene library of the milk-clotting strain Myxococcus xanthus 422 constructed in Escherichia coli allowed the description of eight positive clones containing 26 open reading frames. Only three of them (cltA, cltB, and cltC) encoded proteins that exhibited intracellular milk-clotting ability in E. coli, Saccharomyces cerevisiae, and Pichia pastoris expression systems.

A surface-exposed DraD protein of uropathogenic Escherichia coli bearing Dr fimbriae may be expressed and secreted independently from DraC usher and DraE adhesin

Microbiology ◽  
2005 ◽  
Vol 151 (7) ◽  
pp. 2477-2486 ◽  
Author(s):  
Beata Zalewska ◽  
Rafał Piątek ◽  
Katarzyna Bury ◽  
Alfred Samet ◽  
Bogdan Nowicki ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cell Surface ◽  
Bacterial Cell ◽  
Surface Expression ◽  
Uropathogenic Escherichia Coli ◽  
Bacterial Attachment ◽  
Open Reading Frames ◽  
E Coli ◽  
Fimbrial Subunit ◽  
Reading Frames

The dra gene cluster, expressed by uropathogenic Escherichia coli strains, determines bacterial attachment and invasion. The Dr fimbrial structures formed at the bacterial cell surface are composed of DraE subunits. The Dr fimbriae-coding cluster contains six open reading frames – draA, draB, draC, draD, draP and draE – among which the draE gene encodes the structural fimbrial subunit DraE. Very little is known about E. coli surface expression of the draD gene product. The expression of DraD and its role in the biogenesis of Dr fimbriae were determined by constructing mutants in the dra operon and by immunoblot and immunofluorescence experiments. In this study, DraD was found to be a surface-exposed protein. The expression of DraD was independent of the DraC usher and DraE fimbrial subunits. Polymerization of DraE fimbrial subunits into fimbrial structures did not require expression of the DraD protein.

scholarly journals Altered Distribution of RNA Polymerase Lacking the Omega Subunit within the Prophages along the Escherichia coli K-12 Genome

mSystems ◽  
2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Kaneyoshi Yamamoto ◽  
Yuki Yamanaka ◽  
Tomohiro Shimada ◽  
Paramita Sarkar ◽  
Myu Yoshida ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Rna Polymerase ◽  
Small Subunit ◽  
Open Reading Frames ◽  
Pcr Assay ◽  
E Coli ◽  
K 12 ◽  
Chip Chip ◽  
Reading Frames

The 91-amino-acid-residue small-subunit omega (the rpoZ gene product) of Escherichia coli RNA polymerase plays a structural role in the formation of RNA polymerase (RNAP) as a chaperone in folding the largest subunit (β′, of 1,407 residues in length), but except for binding of the stringent signal ppGpp, little is known of its role in the control of RNAP function. After analysis of genomewide distribution of wild-type and RpoZ-defective RNAP by the ChIP-chip method, we found alteration of the RpoZ-defective RNAP inside open reading frames, in particular, of the genes within prophages. For a set of the genes that exhibited altered occupancy of the RpoZ-defective RNAP, transcription was found to be altered as observed by qRT-PCR assay. All the observations here described indicate the involvement of RpoZ in recognition of some of the prophage genes. This study advances understanding of not only the regulatory role of omega subunit in the functions of RNAP but also the regulatory interplay between prophages and the host E. coli for adjustment of cellular physiology to a variety of environments in nature.

scholarly journals Differential Expression of over 60 Chromosomal Genes in Escherichia coli by Constitutive Expression of MarA

2000 ◽  
Vol 182 (12) ◽  
pp. 3467-3474 ◽  
Author(s):  
Teresa M. Barbosa ◽  
Stuart B. Levy
Keyword(s):  
Escherichia Coli ◽  
Northern Blot Analysis ◽  
Constitutive Expression ◽  
Complete Characterization ◽  
Open Reading Frames ◽  
Altered Expression ◽  
E Coli ◽  
Chromosomal Genes ◽  
Reading Frames

ABSTRACT In Escherichia coli, the MarA protein controls expression of multiple chromosomal genes affecting resistance to antibiotics and other environmental hazards. For a more-complete characterization of the mar regulon, duplicate macroarrays containing 4,290 open reading frames of the E. coli genome were hybridized to radiolabeled cDNA populations derived frommar-deleted and mar-expressing E. coli. Strains constitutively expressing MarA showed altered expression of more than 60 chromosomal genes: 76% showed increased expression and 24% showed decreased expression. Although some of the genes were already known to be MarA regulated, the majority were newly determined and belonged to a variety of functional groups. Some of the genes identified have been associated with iron transport and metabolism; other genes were previously known to be part of thesoxRS regulon. Northern blot analysis of selected genes confirmed the results obtained with the macroarrays. The findings reveal that the mar locus mediates a global stress response involving one of the largest networks of genes described.

scholarly journals Autotransporter Genes pic and tsh Are Associated with Escherichia coli Strains That Cause Acute Pyelonephritis and Are Expressed during Urinary Tract Infection

2004 ◽  
Vol 72 (1) ◽  
pp. 593-597 ◽  
Author(s):  
Susan R. Heimer ◽  
David A. Rasko ◽  
C. Virginia Lockatell ◽  
David E. Johnson ◽  
Harry L. T. Mobley
Keyword(s):  
Escherichia Coli ◽  
Serine Protease ◽  
Open Reading Frames ◽  
Upec Strain ◽  
E Coli ◽  
Reverse Transcription Pcr ◽  
Serine Protease Activity ◽  
Strain Cft073 ◽  
Culture Supernatants ◽  
Reading Frames

ABSTRACT We have identified two chromosomal open reading frames in uropathogenic Escherichia coli (UPEC) strain CFT073 which are highly homologous to serine protease autotransporters Pic and Tsh. Both cloned determinants were correlated with the presence of 105- to 110-kDa proteins in the culture supernatants. Furthermore, in cellular fractionation experiments, 30-kDa polypeptides were identified in the outer membrane; we speculated that these proteins are the β-barrel portions of the autotransporter homologues. Furthermore, Pic-containing culture supernatants have serine protease activity. In reverse transcription-PCR analyses, the expression of the pic and tsh genes in E. coli CFT073 was higher in broth cultures grown at 37°C than at 25°C. Moreover, pic and tsh were expressed by bacteria isolated from urine of transurethrally infected mice. The tsh determinant was identified in 63% of our clinical UPEC strain isolates (n = 87) and in 33% of fecal strains (n = 27), whereas pic was present in 31% of the pyelonephritis (n = 67) and 7% of the fecal strains. There was no significant correlation between cystitis strains (n = 20) and the pic determinant.

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