Browse
Submit Data
Databases
API
Help

Dataset Information

19 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Conformational analysis of the Campylobacter jejuni porin.

ABSTRACT: The major outer membrane protein (MOMP) of Campylobacter jejuni was purified to homogeneity by selective solubilization and fast protein liquid chromatography. The amino acid composition of the MOMP indicates the presence of cysteine residues. The amino-terminal sequence, determined over 31 residues, shows no significant homology with any other porin from gram-negative bacteria except in a discrete region. Immunocross-reactivity between Escherichia coli OmpC and the MOMP was analyzed, and a common antigenic site between these two porins was identified with an anti-peptide antibody. From circular dichroism and immunological investigations, the existence of a stable folded monomer, containing a high level of beta-sheet secondary structure, is evident. Conformational analyses show the presence of a native trimeric state generated by association of the three folded monomers; the stability of this trimer is reduced compared with that of E. coli porins. This study clearly reveals that the C. jejuni MOMP is related to the family of trimeric bacterial porins.

SUBMITTER: Bolla JM

PROVIDER: S-EPMC177172 | biostudies-other | 1995 Aug

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Publications

Conformational analysis of the Campylobacter jejuni porin.

Bolla J M JM Loret E E Zalewski M M Pagés J M JM

Journal of bacteriology 19950801 15

The major outer membrane protein (MOMP) of Campylobacter jejuni was purified to homogeneity by selective solubilization and fast protein liquid chromatography. The amino acid composition of the MOMP indicates the presence of cysteine residues. The amino-terminal sequence, determined over 31 residues, shows no significant homology with any other porin from gram-negative bacteria except in a discrete region. Immunocross-reactivity between Escherichia coli OmpC and the MOMP was analyzed, and a comm ...[more]

PMID: 7543469

Similar Datasets

Purification, characterization and sequence analysis of Omp50,a new porin isolated from Campylobacter jejuni.

Project description:A novel pore-forming protein identified in Campylobacter was purified by ion-exchange chromatography and named Omp50 according to both its molecular mass and its outer membrane localization. We observed a pore-forming ability of Omp50 after re-incorporation into artificial membranes. The protein induced cation-selective channels with major conductance values of 50-60 pS in 1 M NaCl. N-terminal sequencing allowed us to identify the predicted coding sequence Cj1170c from the Campylobacter jejuni genome database as the corresponding gene in the NCTC 11168 genome sequence. The gene, designated omp50, consists of a 1425 bp open reading frame encoding a deduced 453-amino acid protein with a calculated pI of 5.81 and a molecular mass of 51169.2 Da. The protein possessed a 20-amino acid leader sequence. No significant similarity was found between Omp50 and porin protein sequences already determined. Moreover, the protein showed only weak sequence identity with the major outer-membrane protein (MOMP) of Campylobacter, correlating with the absence of antigenic cross-reactivity between these two proteins. Omp50 is expressed in C. jejuni and Campylobacter lari but not in Campylobacter coli. The gene, however, was detected in all three species by PCR. According to its conformation and functional properties, the protein would belong to the family of outer-membrane monomeric porins.

| S-EPMC1221499 | biostudies-other

Functional refolding of the Campylobacter jejuni MOMP (major outer membrane protein) porin by GroEL from the same species.

Project description:Functional and structural studies of outer membrane proteins from Gram-negative bacteria are frequently carried out using refolded proteins. Recombinant proteins are produced in Escherichia coli as inclusion bodies and then tediously refolded by dilution in buffered detergent solutions. In the present work, we obtained the refolding of MOMP (major outer membrane protein) from Campylobacter assisted by the molecular chaperone GroEL. Refolded MOMP recovered its native pore-forming activity when reconstituted in planar lipid bilayers. Both proteins were purified from the Campylobacter jejuni strain 85H. The purity of GroEL was assessed by silver staining and MS. Its native ultrastructure was observed by the use of transmission electron microscopy. Denaturation of MOMP was performed in urea at 65 degrees C followed by dialysis against 100 mM acetic acid, and was assessed by CD analysis. MOMP refolding reached a maximum efficiency in the presence of GroEL (at a MOMP/GroEL molar ratio of 9:1) and ATP. Under these conditions, 95% of denatured MOMP was refolded after a 15 min incubation. This approach represents an alternative method in studies of membrane protein refolding.

| S-EPMC1224022 | biostudies-other

Complete Genome Analysis of Campylobacter jejuni subsp. jejuni Isolated from Bloodstream Infection.

Project description:We report here the complete genome analysis of a clinical Campylobacter jejuni strain sequenced by a hybrid assembly approach. A hybrid assembly approach provided a complete genome sequence of C. jejuni that contains a 1,681,375-bp chromosome and 47,467-bp plasmid carrying various virulence and antimicrobial resistance determinants.

| S-EPMC7975872 | biostudies-literature

A proteome-wide screen of Campylobacter jejuni using protein microarrays identifies novel and conformational antigens.

Project description:Campylobacter jejuni (C. jejuni) is a foodborne intestinal pathogen and major cause of gastroenteritis worldwide. C. jejuni proteins that are immunogenic have been sought for their potential use in the development of biomarkers, diagnostic assays, or subunit vaccines for humans or livestock. To identify new immunogenic C. jejuni proteins, we used a native protein microarray approach. A protein chip, with over 1400 individually purified GST-tagged C. jejuni proteins, representing over 86% of the proteome, was constructed to screen for antibody titers present in test sera raised against whole C. jejuni cells. Dual detection of GST signals was incorporated as a way of normalizing the variation of protein concentrations contributing to the antibody staining intensities. We detected strong signals to 102 C. jejuni antigens. In addition to antigens recognized by antiserum raised against C. jejuni, parallel experiments were conducted to identify antigens cross-reactive to antiserum raised against various serotypes of E. coli or Salmonella or to healthy human sera. This led to the identification of 34 antigens specifically recognized by the C. jejuni antiserum, only four of which were previously known. The chip approach also allowed identification of conformational antigens. We demonstrate in the case of Cj1621 that antigen signals are lost to denaturing conditions commonly used in other approaches to identify immunogens. Antigens identified in this study include those possessing sequence features indicative of cell surface localization, as well as those that do not. Together, our results indicate that the unbiased chip-based screen can help reveal the full repertoire of host antibodies against microbial proteomes.

| S-EPMC6329530 | biostudies-literature

Quantitative RNA-seq analysis of the Campylobacter jejuni transcriptome.

Project description:Campylobacter jejuni is the most common bacterial cause of foodborne disease in the developed world. Its general physiology and biochemistry, as well as the mechanisms enabling it to colonize and cause disease in various hosts, are not well understood, and new approaches are required to understand its basic biology. High-throughput sequencing technologies provide unprecedented opportunities for functional genomic research. Recent studies have shown that direct Illumina sequencing of cDNA (RNA-seq) is a useful technique for the quantitative and qualitative examination of transcriptomes. In this study we report RNA-seq analyses of the transcriptomes of C. jejuni (NCTC11168) and its rpoN mutant. This has allowed the identification of hitherto unknown transcriptional units, and further defines the regulon that is dependent on rpoN for expression. The analysis of the NCTC11168 transcriptome was supplemented by additional proteomic analysis using liquid chromatography-MS. The transcriptomic and proteomic datasets represent an important resource for the Campylobacter research community.

| S-EPMC3353397 | biostudies-literature

Campylobacter jejuni Cj1000 regulon

Project description:Transcriptional regulation mediates adaptation of pathogens to environmental stimuli and is important for host colonisation. The Campylobacter jejuni genome sequence reveals a surprisingly small set of regulators, mostly of unknown function, suggesting an intricate regulatory network. Interestingly, C. jejuni lacks the homologues of ubiquitous regulators involved in stress response found in many other Gram-negative bacteria. Nonetheless, cj1000 is predicted to code for the sole LysR-type regulator in the C. jejuni genome, and thus may be involved in major adaptation pathways. A cj1000 mutant strain was constructed and found to be attenuated in its ability to colonise 1-day old chicks. Complementation of cj1000 mutation restored the colonisation ability to that of wild type levels. The mutant strain was also outcompeted in a competitive colonisation assay of the piglet intestine. High resolution oxygraphy was carried out for the first time on C. jejuni and revealed a role for Cj1000 in controlling O2 consumption. Furthermore, microarray analysis of the cj1000 mutant revealed both direct and indirect regulatory targets, including genes involved in energy metabolism and oxidative stress defences. These results highlight the importance of Cj1000 regulation in host colonisation and in major physiological pathways.

2013-07-03 | GSE43792 | GEO

Campylobacter jejuni butyrate resopnse

Project description:Growth of Campylobacter jejuni in butyrate, including deletions of a TCS involved in sensing this response

2021-01-01 | GSE142852 | GEO

Inflammasome activation by Campylobacter jejuni.

Project description:The Gram-negative pathogen Campylobacter jejuni is the most common cause of bacterial foodborne disease worldwide. The mechanisms that lead to bacterial invasion of eukaryotic cells and massive intestinal inflammation are still unknown. In this study, we report that C. jejuni infection of mouse macrophages induces upregulation of pro-IL-1? transcript and secretion of IL-1? without eliciting cell death. Immunoblotting indicated cleavage of caspase-1 and IL-1? in infected cells. In bone marrow-derived macrophages from different knockout mice, IL-1? secretion was found to require NLRP3, ASC, and caspase-1/11 but not NLRC4. In contrast to NLRP3 activation by ATP, C. jejuni activation did not require priming of these macrophages. C. jejuni also activated the NLRP3 inflammasome in human macrophages as indicated by the presence of ASC foci and caspase-1-positive cells. Analysis of a vast array of C. jejuni mutants with defects in capsule formation, LPS biosynthesis, chemotaxis, flagella synthesis and flagellin (-like) secretion, type 6 secretion system needle protein, or cytolethal distending toxin revealed a direct correlation between the number of intracellular bacteria and NLRP3 inflammasome activation. The C. jejuni invasion-related activation of the NLRP3 inflammasome without cytotoxicity and even in nonprimed cells extends the known repertoire of bacterial inflammasome activation and likely contributes to C. jejuni-induced intestinal inflammation.

| S-EPMC4201959 | biostudies-literature

Essential genome of Campylobacter jejuni.

Project description:Campylobacter species are a leading cause of bacterial foodborne illness worldwide. Despite the global efforts to curb them, Campylobacter infections have increased continuously in both developed and developing countries. The development of effective strategies to control the infection by this pathogen is warranted. The essential genes of bacteria are the most prominent targets for this purpose. In this study, we used transposon sequencing (Tn-seq) of a genome-saturating library of Tn5 insertion mutants to define the essential genome of C. jejuni at a high resolution.We constructed a Tn5 mutant library of unprecedented complexity in C. jejuni NCTC 11168 with 95,929 unique insertions throughout the genome and used the genomic DNA of the library for the reconstruction of Tn5 libraries in the same (C. jejuni NCTC 11168) and different strain background (C. jejuni 81-176) through natural transformation. We identified 166 essential protein-coding genes and 20 essential transfer RNAs (tRNA) in C. jejuni NCTC 11168 which were intolerant to Tn5 insertions during in vitro growth. The reconstructed C. jejuni 81-176 library had 384 protein coding genes with no Tn5 insertions. Essential genes in both strain backgrounds were highly enriched in the cluster of orthologous group (COG) categories of 'Translation, ribosomal structure and biogenesis (J)', 'Energy production and conversion (C)', and 'Coenzyme transport and metabolism (H)'.Comparative analysis among this and previous studies identified 50 core essential genes of C. jejuni, which can be further investigated for the development of novel strategies to control the spread of this notorious foodborne bacterial pathogen.

| S-EPMC5557513 | biostudies-literature

Campylobacter jejuni and Campylobacter coli genotyping by high-resolution melting analysis of a flaA fragment.

Project description:The highly variable flagellin-encoding flaA gene has long been used for genotyping Campylobacter jejuni and Campylobacter coli. High-resolution melting (HRM) analysis is emerging as an efficient and robust method for discriminating DNA sequence variants. The objective of this study was to apply HRM analysis to flaA-based genotyping. The initial aim was to identify a suitable flaA fragment. It was found that the PCR primers commonly used to amplify the flaA short variable repeat (SVR) yielded a mixed PCR product unsuitable for HRM analysis. However, a PCR primer set composed of the upstream primer used to amplify the fragment used for flaA restriction fragment length polymorphism (RFLP) analysis and the downstream primer used for flaA SVR amplification generated a very pure PCR product, and this primer set was used for the remainder of the study. Eighty-seven C. jejuni and 15 C. coli isolates were analyzed by flaA HRM and also partial flaA sequencing. There were 47 flaA sequence variants, and all were resolved by HRM analysis. The isolates used had previously also been genotyped using single-nucleotide polymorphisms (SNPs), binary markers, CRISPR HRM, and flaA RFLP. flaA HRM analysis provided resolving power multiplicative to the SNPs, binary markers, and CRISPR HRM and largely concordant with the flaA RFLP. It was concluded that HRM analysis is a promising approach to genotyping based on highly variable genes.

| S-EPMC2805211 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data