scholarly journals It takes two to tango: two TatA paralogues and two redox enzyme-specific chaperones are involved in the localization of twin-arginine translocase substrates in Campylobacter jejuni

Microbiology ◽  
2014 ◽  
Vol 160 (9) ◽  
pp. 2053-2066 ◽  
Author(s):  
Yang-Wei Liu ◽  
Andrew Hitchcock ◽  
Robert C. Salmon ◽  
David J. Kelly
Keyword(s):  
Nitrate Reductase ◽  
Campylobacter Jejuni ◽  
Formate Dehydrogenase ◽  
Specific Rate ◽  
Peptide Cleavage ◽  
Food Borne ◽  
Sulphite Oxidase ◽  
Strain Nctc ◽  
Electron Transport Chains ◽  
Twin Arginine Translocase

The food-borne zoonotic pathogen Campylobacter jejuni has complex electron transport chains required for growth in the host, many of which contain cofactored periplasmic enzymes localized by the twin-arginine translocase (TAT). We report here the identification of two paralogues of the TatA translocase component in C. jejuni strain NCTC 11168, encoded by cj1176c (tatA1) and cj0786 (tatA2). Deletion mutants constructed in either or both of the tatA1 and tatA2 genes displayed distinct growth and enzyme activity phenotypes. For sulphite oxidase (SorAB), the multi-copper oxidase (CueO) and alkaline phosphatase (PhoX), complete dependency on TatA1 for correct periplasmic activity was observed. However, the activities of nitrate reductase (NapA), formate dehydrogenase (FdhA) and trimethylamine N-oxide reductase (TorA) were significantly reduced in the tatA2 mutant. In contrast, the specific rate of fumarate reduction catalysed by the flavoprotein subunit of the methyl menaquinone fumarate reductase (MfrA) was similar in periplasmic fractions of both the tatA1 and the tatA2 mutants and only the deletion of both genes abolished activity. Nevertheless, unprocessed MfrA accumulated in the periplasm of the tatA1 (but not tatA2) mutant, indicating aberrant signal peptide cleavage. Surprisingly, TatA2 lacks two conserved residues (Gln8 and Phe39) known to be essential in Escherichia coli TatA and we suggest it is unable to function correctly in the absence of TatA1. Finally, only two TAT chaperones (FdhM and NapD) are encoded in strain NCTC 11168, which mutant studies confirmed are highly specific for formate dehydrogenase and nitrate reductase assembly, respectively. Thus, other TAT substrates must use general chaperones in their biogenesis.

scholarly journals Campylobacter jejuni proteins Cj0952c and Cj0951c affect chemotactic behaviour towards formic acid and are important for invasion of host cells

Microbiology ◽  
2010 ◽  
Vol 156 (10) ◽  
pp. 3123-3135 ◽  
Author(s):  
A. Malik Tareen ◽  
Javid Iqbal Dasti ◽  
Andreas E. Zautner ◽  
Uwe Groß ◽  
Raimond Lugert
Keyword(s):  
Formic Acid ◽  
Campylobacter Jejuni ◽  
Formate Dehydrogenase ◽  
Bacterial Pathogen ◽  
Host Cells ◽  
Industrialized Countries ◽  
Transposon Insertion ◽  
Food Borne ◽  
Strain Nctc ◽  
Chemotactic Behaviour

Campylobacter jejuni, an important food-borne bacterial pathogen in industrialized countries and in the developing world, is one of the major causes of bacterial diarrhoea. To identify genes which are important for the invasion of host cells by the pathogen, we screened altogether 660 clones of a transposon-generated mutant library based on the clinical C. jejuni isolate B2. Thereby, we identified a clone with a transposon insertion in gene cj0952c. As in the well-characterized C. jejuni strain NCTC 11168, the corresponding protein together with the gene product of the adjacent gene cj0951c consists of two transmembrane domains, a HAMP domain and a putative MCP domain, which together are thought to act as a chemoreceptor, designated Tlp7. In this report we show that genes cj0952c and cj0951c (i) are important for the host cell invasion of the pathogen, (ii) are not translated as one protein in C. jejuni isolate B2, contradicting the idea of a postulated read-through mechanism, (iii) affect the motility of C. jejuni, (iv) alter the chemotactic behaviour of the pathogen towards formic acid, and (v) are not related to the utilization of formic acid by formate dehydrogenase.

scholarly journals Roles of the twin-arginine translocase and associated chaperones in the biogenesis of the electron transport chains of the human pathogen Campylobacter jejuni

Microbiology ◽  
2010 ◽  
Vol 156 (10) ◽  
pp. 2994-3010 ◽  
Author(s):  
Andrew Hitchcock ◽  
Stephen J. Hall ◽  
Jonathan D. Myers ◽  
Francis Mulholland ◽  
Michael A. Jones ◽  
...  
Keyword(s):  
Electron Transport ◽  
Campylobacter Jejuni ◽  
Reactive Nitrogen Species ◽  
Formate Dehydrogenase ◽  
Nitrosative Stress ◽  
Nitrite Reduction ◽  
Enzyme Assays ◽  
Wild Type ◽  
Electron Transport Chains ◽  
Twin Arginine Translocase

The zoonotic pathogen Campylobacter jejuni NCTC 11168 uses a complex set of electron transport chains to ensure growth with a variety of electron donors and alternative electron acceptors, some of which are known to be important for host colonization. Many of the key redox proteins essential for electron transfer in this bacterium have N-terminal twin-arginine translocase (TAT) signal sequences that ensure their transport across the cytoplasmic membrane in a folded state. By comparisons of 2D gels of periplasmic extracts, gene fusions and specific enzyme assays in wild-type, tatC mutant and complemented strains, we experimentally verified the TAT dependence of 10 proteins with an N-terminal twin-arginine motif. NrfH, which has a TAT-like motif (LRRKILK), was functional in nitrite reduction in a tatC mutant, and was correctly rejected as a TAT substrate by the tatfind and TatP prediction programs. However, the hydrogenase subunit HydA is also rejected by tatfind, but was shown to be TAT-dependent experimentally. The YedY homologue Cj0379 is the only TAT translocated molybdoenzyme of unknown function in C. jejuni; we show that a cj0379c mutant is deficient in chicken colonization and has a nitrosative stress phenotype, suggestive of a possible role for Cj0379 in the reduction of reactive nitrogen species in the periplasm. Only two potential TAT chaperones, NapD and Cj1514, are encoded in the genome. Surprisingly, despite homology to TorD, Cj1514 was shown to be specifically required for the activity of formate dehydrogenase, not trimethylamine N-oxide reductase, and was designated FdhM.

scholarly journals Structural genes for nitrate-inducible formate dehydrogenase in Escherichia coli K-12.

Genetics ◽  
1990 ◽  
Vol 125 (4) ◽  
pp. 691-702 ◽  
Author(s):  
B L Berg ◽  
V Stewart
Keyword(s):  
Escherichia Coli ◽  
Nitrate Reductase ◽  
Formate Dehydrogenase ◽  
Recombinant Dna ◽  
Structural Genes ◽  
Respiratory Pathway ◽  
E Coli ◽  
Formate Oxidation ◽  
Operon Expression ◽  
K 12

Abstract Formate oxidation coupled to nitrate reduction constitutes a major anaerobic respiratory pathway in Escherichia coli. This respiratory chain consists of formate dehydrogenase-N, quinone, and nitrate reductase. We have isolated a recombinant DNA clone that likely contains the structural genes, fdnGHI, for the three subunits of formate dehydrogenase-N. The fdnGHI clone produced proteins of 110, 32 and 20 kDa which correspond to the subunit sizes of purified formate dehydrogenase-N. Our analysis indicates that fdnGHI is organized as an operon. We mapped the fdn operon to 32 min on the E. coli genetic map, close to the genes for cryptic nitrate reductase (encoded by the narZ operon). Expression of phi(fdnG-lacZ) operon fusions was induced by anaerobiosis and nitrate. This induction required fnr+ and narL+, two regulatory genes whose products are also required for the anaerobic, nitrate-inducible activation of the nitrate reductase structural gene operon, narGHJI. We conclude that regulation of fdnGHI and narGHJI expression is mediated through common pathways.

The structures of the lipooligosaccharide and capsule polysaccharide of Campylobacter jejuni genome sequenced strain NCTC 11168

2002 ◽  
Vol 269 (21) ◽  
pp. 5119-5136 ◽  
Author(s):  
Frank St. Michael ◽  
Christine M. Szymanski ◽  
Jianjun Li ◽  
Kenneth H. Chan ◽  
Nam Huan Khieu ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Strain Nctc

scholarly journals Biofilm Formation by Campylobacter jejuni Is Increased under Aerobic Conditions

2010 ◽  
Vol 76 (7) ◽  
pp. 2122-2128 ◽  
Author(s):  
Mark Reuter ◽  
Arthur Mallett ◽  
Bruce M. Pearson ◽  
Arnoud H. M. van Vliet
Keyword(s):  
Campylobacter Jejuni ◽  
Food Chain ◽  
Biofilm Formation ◽  
Planktonic Cells ◽  
Aerobic Conditions ◽  
Food Borne ◽  
Passive Release ◽  
Bacterial Gastroenteritis ◽  
Microaerobic Conditions ◽  
Developed World

ABSTRACT The microaerophilic human pathogen Campylobacter jejuni is the leading cause of food-borne bacterial gastroenteritis in the developed world. During transmission through the food chain and the environment, the organism must survive stressful environmental conditions, particularly high oxygen levels. Biofilm formation has been suggested to play a role in the environmental survival of this organism. In this work we show that C. jejuni NCTC 11168 biofilms developed more rapidly under environmental and food-chain-relevant aerobic conditions (20% O2) than under microaerobic conditions (5% O2, 10% CO2), although final levels of biofilms were comparable after 3 days. Staining of biofilms with Congo red gave results similar to those obtained with the commonly used crystal violet staining. The level of biofilm formation by nonmotile aflagellate strains was lower than that observed for the motile flagellated strain but nonetheless increased under aerobic conditions, suggesting the presence of flagellum-dependent and flagellum-independent mechanisms of biofilm formation in C. jejuni. Moreover, preformed biofilms shed high numbers of viable C. jejuni cells into the culture supernatant independently of the oxygen concentration, suggesting a continuous passive release of cells into the medium rather than a condition-specific active mechanism of dispersal. We conclude that under aerobic or stressful conditions, C. jejuni adapts to a biofilm lifestyle, allowing survival under detrimental conditions, and that such a biofilm can function as a reservoir of viable planktonic cells. The increased level of biofilm formation under aerobic conditions is likely to be an adaptation contributing to the zoonotic lifestyle of C. jejuni.

scholarly journals Role of Campylobacter jejuni Respiratory Oxidases and Reductases in Host Colonization

2008 ◽  
Vol 74 (5) ◽  
pp. 1367-1375 ◽  
Author(s):  
Rebecca A. Weingarten ◽  
Jesse L. Grimes ◽  
Jonathan W. Olson
Keyword(s):  
Campylobacter Jejuni ◽  
Anaerobic Respiration ◽  
Wild Type ◽  
Respiratory Enzymes ◽  
Host Colonization ◽  
Enzymatic Function ◽  
Food Borne ◽  
Transport Chain ◽  
Respiratory Oxidases

ABSTRACT Campylobacter jejuni is the leading cause of human food-borne bacterial gastroenteritis. The C. jejuni genome sequence predicts a branched electron transport chain capable of utilizing multiple electron acceptors. Mutants were constructed by disrupting the coding regions of the respiratory enzymes nitrate reductase (napA::Cm), nitrite reductase (nrfA::Cm), dimethyl sulfoxide, and trimethylamine N-oxide reductase (termed Cj0264::Cm) and the two terminal oxidases, a cyanide-insensitive oxidase (cydA::Cm) and cbb3-type oxidase (ccoN::Cm). Each strain was characterized for the loss of the associated enzymatic function in vitro. The strains were then inoculated into 1-week-old chicks, and the cecal contents were assayed for the presence of C. jejuni 2 weeks postinoculation. cydA::Cm and Cj0264c::Cm strains colonized as well as the wild type; napA::Cm and nrfA::Cm strains colonized at levels significantly lower than the wild type. The ccoN::Cm strain was unable to colonize the chicken; no colonies were recovered at the end of the experiment. While there appears to be a role for anaerobic respiration in host colonization, oxygen is the most important respiratory acceptor for C. jejuni in the chicken cecum.

scholarly journals Campylobacter jejuni persistently colonizes gnotobiotic altered Schaedler flora C3H/HeN mice and induces mild colitis

2020 ◽  
Vol 367 (20) ◽  
Author(s):  
Meghan Wymore Brand ◽  
Orhan Sahin ◽  
Jesse M Hostetter ◽  
Julian Trachsel ◽  
Qijing Zhang ◽  
...  
Keyword(s):  
Animal Models ◽  
Campylobacter Jejuni ◽  
Gastrointestinal Disease ◽  
Proximal Colon ◽  
Rodent Model ◽  
Mucosal Inflammation ◽  
Colonization Resistance ◽  
Food Borne ◽  
Bacterial Gastroenteritis

ABSTRACT Campylobacter jejuni is a major cause of food-borne human bacterial gastroenteritis but animal models for C. jejuni mediated disease remain limited because C. jejuni poorly colonizes immunocompetent, conventionally-reared (Conv-R) mice. Thus, a reliable rodent model (i.e. persistent colonization) is desirable in order to evaluate C. jejuni-mediated gastrointestinal disease and mechanisms of pathogenicity. As the nature and complexity of the microbiota likely impacts colonization resistance for C. jejuni, Conv-R and gnotobiotic C3H/HeN mice were used to evaluate the persistence of C. jejuni colonization and development of disease. A total of four C. jejuni isolates readily and persistently colonized ASF mice and induced mild mucosal inflammation in the proximal colon, but C. jejuni did not stably colonize nor induce lesions in Conv-R mice. This suggests that the pathogenesis of C. jejuni is influenced by the microbiota, and that ASF mice offer a reproducible model to study the influence of the microbiota on the ability of C. jejuni to colonize the gut and to mediate gastroenteritis.

scholarly journals THE SYNTHESIS OF FORMATE DEHYDROGENASE AND NITRATE REDUCTASE PROTEINS IN VARIOUS fdb AND cbl MUTANTS OFESCHERICHIA COLI

1980 ◽  
Vol 7 (2) ◽  
pp. 145-151 ◽  
Author(s):  
ALEXANDER GRAHAM ◽  
HAZEL E. JENKINS ◽  
NOEL H. SMITH ◽  
MARIE-ANDRÉE MANDRAND-BERTHELOT ◽  
BRUCE A. HADDOCK ◽  
...  
Keyword(s):  
Nitrate Reductase ◽  
Formate Dehydrogenase ◽  
Ofescherichia Coli

Activation of nit-1 nitrate reductase by W-formate dehydrogenase

1984 ◽  
Vol 121 (3) ◽  
pp. 1042-1047 ◽  
Author(s):  
Joseph C. Deaton ◽  
Edward I. Solomon ◽  
Charles N. Durfor ◽  
Phyllis J. Wetherbee ◽  
Barbara K. Burgess ◽  
...  
Keyword(s):  
Nitrate Reductase ◽  
Formate Dehydrogenase
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