Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0043167 (pertussis)
 19,595 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Antibiotic-resistant and auxotrophic mutants of Bordetella pertussis were isolated. These were used as recipients for the uptake from Escherichia coli of broad-host-range R plasmids R68.45, RP1, and RP1 and RP4 carrying transposons Tn501 and Tn7 respectively. B. pertussis transconjugants from these crosses were used as donors to mobilize StrR, NalR, thr+ and gly+ chromosomal markers to B. pertussis or to B. parapertussis recipient strains. The frequency of plasmid transfer varied and depended on the donor and recipient strains used. Differences in chromosome mobilization frequencies of individual markers were observed and appeared to depend on the presence or absence of transposons Tn501 and Tn7 on the plasmid. Linkage was detected between the gly+ and NalR markers.
 ...
PMID:R-plasmid-mediated chromosome mobilization in Bordetella pertussis. 288 25

Conjugative transfer of DNA that occurs between bacteria also operates between bacteria and higher organisms. The transfer of DNA between Gram-negative bacteria requires initial contact by a sex pilus followed by DNA traversing four membranes (donor plus recipient) using a transmembrane pore. Accumulating evidence suggests that transfer of the T-DNA from Agrobacterium tumefaciens to plants may also occur via a conjugative mechanism. The virB operon of the Ti plasmid exhibits close homologies to genes that are known to encode the pilin subunits and pilin assembly proteins. The proteins encoded by the PilW operon of IncW plasmid R388 share strong similarities (average similarity = 50.8%) with VirB proteins. Similarly, the TraA, TraL and TraC proteins of IncF plasmid F have similarities to VirB2, VirB3 and VirB4 respectively (average similarity = 45.3%). VirB2 protein (12.3 kDa) contains a signal peptidase-I cleavage sequence that generates a polypeptide of 7.2 kDa. Likewise, the 12.8 kDa propilin protein TraA of plasmid F also possesses a peptidase-I cleavage site that generates the 7.2 kDa pilin structural protein. Similar amino acid sequences of the conjugative transfer genes of F, R388 as well as plasmid RP4 and the genes of the ptI operon of Bortedella pertussis suggest the existence of a superfamily of transmembrane proteins adapted to the promiscuous transfer of DNA-protein complexes.
 ...
PMID:Promiscuous DNA transfer system of Agrobacterium tumefaciens: role of the virB operon in sex pilus assembly and synthesis. 791 64

The gram-negative bacterial pathogen Helicobacter pylori, an important aetiological agent of gastroduodenal disease in humans, belongs to a group of bacterial species displaying competence for genetic transformation. Here, we describe the comB gene locus of H. pylori involved in DNA transformation competence. It consists of a cluster of four tandemly arranged genes with partially overlapping open reading frames, orf2, comB1, comB2 and comB3, constituting a single transcriptional unit. Orf2 encodes a 37-amino-acid peptide carrying a signal sequence, whereas comB1, comB2 and comB3 produce 29 kDa, 38 kDa and 42 kDa proteins, respectively, as demonstrated by immunoblotting with specific antisera. For Orf2 and ComB1, no homologous proteins were identified in the database. For ComB3, the best homologies were found with TraS/TraB from the Pseudomonas aeruginosa conjugative plasmid RP1 and TrbI of plasmid RP4, VirB10 from the Ti plasmid of Agrobacterium tumefaciens and PtlG, a protein involved in secretion of pertussis toxin of Bordetella pertussis. Defined transposon knock-out mutants in individual comB genes resulted in transformation-defective phenotypes ranging from a 90% reduction to a complete loss of the natural transformation efficiency. The comB2 and comB3 genes show homology to HP0528 and HP0527, respectively, located on the cagII pathogenicity island of H. pylori strain 26695.
 ...
PMID:Natural competence for DNA transformation in Helicobacter pylori: identification and genetic characterization of the comB locus. 966 88

The clinical isolate Corynebacterium striatum M82B (formerly Corynebacterium xerosis M82B) carries the 50-kb R-plasmid pTP10 conferring resistance to the antibiotics chloramphenicol, erythromycin, kanamycin, and tetracycline. DNA sequence analysis of the chloramphenicol resistance region revealed the presence of the 4155-bp transposable element Tn5564. The ends of Tn5564 are identical 22-bp inverted repeats flanked by a 6-bp target site duplication. The central region of Tn5564 encodes the chloramphenicol resistance gene cmx, specifying a transmembrane chloramphenicol efflux protein, and an open reading frame homologous to transposases of insertion sequences identified in Arthrobacter nicotinovorans and Bordetella pertussis. Furthermore, the 1715-bp insertion sequence IS1513 encoding a putative transposase of the IS30 family is an integral part of Tn5564 and is located upstream of cmx. For transposon mutagenesis, Tn5564 was transferred to Corynebacterium glutamicum on a mobilizable Escherichia coli plasmid using RP4-mediated intergeneric conjugation. Transposition of Tn5564 in C. glutamicum occurred with a frequency of 3.3 x 10(-8) and resulted in an insertion into target sites containing the central palindromic tetranucleotide CTAG. A Tn5564-induced mutant strain of C. glutamicum was found to carry the transposon in the ftsZ gene region.
 ...
PMID:Corynebacterium striatum chloramphenicol resistance transposon Tn5564: genetic organization and transposition in Corynebacterium glutamicum. 973 14

Type IV secretion systems (TFSS) mediate secretion or direct cell-to-cell transfer of virulence factors (proteins or protein-DNA complexes) from many Gram-negative animal, human and plant pathogens, such as Agrobacterium tumefaciens, Bartonella tribocorum, Bordetella pertussis, Brucella suis, Helicobacter pylori, Legionella pneumophila and Rickettsia prowazekii, into eukaryotic cells. Bacterial conjugation is also classified as a TFSS-like process mediating the spread of broad-host-range plasmids between Gram-negative bacteria such as RP4 and R388, which carry antibiotic resistance genes. Genetic, biochemical, cell biological and structural biology experiments led to significant progress in the understanding of several aspects of TFSS processes. X-ray crystallography revealed that homologues of the A. tumefaciens inner membrane-associated proteins VirB11 and VirD4 from H. pylori and R388, respectively, may form channels for substrate translocation or assembly of the transmembrane TFSS machinery. Biochemical and cell biological experiments revealed interactions between components of the periplasmic core components VirB8, VirB9 and VirB10, which may form the translocation channel. Analysis of A. tumefaciens virulence proteins VirE2 and VirF suggested that the periplasmic translocation route of the pertussis toxin from B. pertussis may be more generally valid than previously anticipated. Secretion and modification of toxins from H. pylori and L. pneumophila profoundly affect host cell metabolism, thus entering the discipline of cellular microbiology. Finally, results from genome sequencing projects revealed the presence of up to three TFSS in a single organism, and the analysis of their interplay and adaptation to different functions will be a future challenge. TFSS-carrying plasmids were discovered in different ecosystems, suggesting that genetic exchange may speed up their evolution and adaptation to different cell-cell interactions.
 ...
PMID:Bacterial secrets of secretion: EuroConference on the biology of type IV secretion processes. 1191 19