Structure and function of repetitive sequence elements associated with a highly polymorphic domain of the <i>Neisseria meningitidis</i> PilQ protein

Tønjum, Tone; Caugant, Dominique A.; Dunham, Stephen; Koomey, Michael

doi:10.1046/j.1365-2958.1998.00910.x

Cited by 61 publications

(82 citation statements)

References 48 publications

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“…Meningococcal strains were grown as previously described (Tønjum et al, 1995). The M1080-DpilQ mutant has a transposon insertion in the pilQ start codon (Tonjum et al, 1998). The Mc-2 mutant is a chimeric strain in which the SBR region of the PilQ monomer is replaced by the corresponding but non-homologous region from P. aeruginosa PilQ (Tønjum et al, 1998).…”

Section: Methodsmentioning

confidence: 99%

“…The M1080-DpilQ mutant has a transposon insertion in the pilQ start codon (Tonjum et al, 1998). The Mc-2 mutant is a chimeric strain in which the SBR region of the PilQ monomer is replaced by the corresponding but non-homologous region from P. aeruginosa PilQ (Tønjum et al, 1998). The plasmid pUP6 (Wolfgang et al, 1999) is a derivative of pHSS6 (Seifert et al, 1990), and contains two neisserial DNA-uptake sequences as an inverted repeat.…”

Section: Methodsmentioning

confidence: 99%

“…The MICs to vancomycin of exhibited the same vancomycin-resistant phenotype as WT meningococci (32 mg ml 21 ). However, a meningococcal PilQ chimera, Mc-Pa-2, in which the SBR region is replaced by the corresponding but non-homologous region of P. aeruginosa PilQ (Tønjum et al, 1998), exhibited an MIC to vancomycin of >256 mg ml 21 . The permeability of fluorescence-labelled vancomycin was also monitored by flow cytometry in the WT and the PilQ chimera Mc-Pa-2.…”

Section: Mutation Of the Sbr Region Of Pilq Increases Channel Permeabmentioning

confidence: 99%

“…An integral element in these processes is the PilQ multimer. PilQ is an antigenically conserved outermembrane protein (Corbett et al, 1988;Hansen & Wilde, 1984), which is essential for meningococcal pilus expression at the cell surface (Tønjum et al, 1998). Meningococcal PilQ is unique among secretins because of its abundance in the outer membrane, and the presence in its N-terminal domain of four to seven copies of an octapeptide, PAKQQAAA, termed small basic repeats (SBRs) (Tønjum et al, 1998).…”

Section: Introductionmentioning

confidence: 99%

“…PilQ is an antigenically conserved outermembrane protein (Corbett et al, 1988;Hansen & Wilde, 1984), which is essential for meningococcal pilus expression at the cell surface (Tønjum et al, 1998). Meningococcal PilQ is unique among secretins because of its abundance in the outer membrane, and the presence in its N-terminal domain of four to seven copies of an octapeptide, PAKQQAAA, termed small basic repeats (SBRs) (Tønjum et al, 1998). We previously purified the PilQ oligomer from meningococcal outer membranes, and showed that it forms a symmetric structure of approximately 900 kDa, consisting of 12 identical subunits (Collins et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

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Topology of the outer-membrane secretin PilQ from Neisseria meningitidis

et al. 2006

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Neisseria meningitidis is the causative agent of epidemic meningococcal meningitis and septicaemia. Type IV pili are surface organelles that mediate a variety of functions, including adhesion, twitching motility, and competence for DNA binding and uptake in transformation. The secretin PilQ is required for type IV pilus expression at the cell surface, and forms a dodecameric cage-like macromolecular complex in the meningococcal outer membrane. PilQ-null mutants are devoid of surface pili, and prevailing evidence suggests that the PilQ complex facilitates extrusion and retraction of type IV pili across the outer membrane. Defining the orientation of the meningococcal PilQ complex in the membrane is a prerequisite for understanding the structure-function relationships of this important protein in pilus biology. In order to begin to define the topology of the PilQ complex in the outer membrane, polyhistidine insertions in N-and C-terminal regions of PilQ were constructed, and their subcellular locations examined. Notably, the insertion epitopes at residues 205 and 678 were located within the periplasm, whereas residue 656 was exposed at the outer surface of the outer membrane. Using electron microscopy with Ni-NTA gold labelling, it was demonstrated that the insertion at residue 205 within the N-terminus mapped to a site on the arm-like features of the 3D structure of the PilQ multimer. Interestingly, mutation of the same region gave rise to an increase in vancomycin permeability through the PilQ complex. The results yield novel information on the PilQ N-terminal location and function in the periplasm, and reveal a complex organization of the membrane-spanning secretin in vivo.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Mutation Of the Sbr Region Of Pilq Increases Channel Permeabmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Topology of the outer-membrane secretin PilQ from Neisseria meningitidis

et al. 2006

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Neisseria

Tønjum¹

2015

Bergey's Manual of Systematics of Archaea and Bacteria

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Neis.se' ri.a . M.L. fem. n. Neisseria named after Albert Neisser, who discovered the etiological agent of gonorrhea in the pus of patients in 1889. Proteobacteria / Betaproteobacteria / Neisseriales / Neisseriaceae / Neisseria Cocci 0.6–1.9 µm in diameter, occurring singly but often in pairs with adjacent sides flattened; two species ( Neisseria elongata and N . weaveri ) are exceptions and consist of short rods 0.5 µm wide, often arranged as diplobacilli or in chains. Division of the coccal species is in two planes at right angles to each other, sometimes resulting in tetrads. Capsules and fimbriae (pili) may be present. Endospores are not present. Gram negative, but there is a tendency to resist decolorization. Swimming motility does not occur and flagella are absent. Aerobic. Some species produce a yellow carotenoid pigment. Some species are nutritionally fastidious and hemolytic. Optimal temperature, 35–37°C. Oxidase positive. Catalase positive except most strains of N . elongata . Carbonic anhydrase is produced by all species. All species reduce nitrite except N . gonorrhoeae and N . canis . Neisseria spp. produce acid from carbohydrates by oxidation, not fermentation. Chemoorganotrophic. Exotoxins are not produced. Some species are saccharolytic. Inhabitants of the mucous membranes of mammals. Some species are primary pathogens of humans. The genus Neisseria belongs to the family Neisseriaceae of the Betaproteobacteria . The mol % G + C of the DNA is : 48–56. Type species : Neisseria gonorrhoeae (Zopf 1885) Trevisan 1885, 106 ( Merismopedia gonorrhoeae Zopf 1885, 54.)

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