Identification of a DNA transformation gene required for com101A+ expression and supertransformer phenotype in Haemophilus influenzae.

Zulty, James J.; Barcak, Gerard J.

doi:10.1073/pnas.92.8.3616

Cited by 44 publications

(61 citation statements)

References 20 publications

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“…This possibility would bypass a requirement for the addition of exogenous cAMP to increase transformation efficiency. A similar result was reported for cloned tfoX on a plasmid in H. influenzae (Zulty and Barcak, 1995).…”

Section: Discussionsupporting

confidence: 86%

“…1). The tfoX gene of A. actinomycetemcomitans shares many properties with the tfoX gene from H. influenzae (Zulty and Barcak, 1995). It has two potential ribosome-binding sites and can give a protein of 24.0 kDa, which is similar to what is observed in H. influenzae.…”

Section: The Tfox (Sxy) Gene Of a Actinomycetemcomitansmentioning

confidence: 82%

“…Comparison of the tfoX regions of A. actinomycetemcomitans and H. influenzae (Section 2.3). A. Nucleotide sequences of the regions upstream and downstream of the tfoX structural gene, which is delimited by "start" and "stop," from A. actinomycetemcomitans HK1651 (Roe et al, 2006) and H. influenzae Rd (Zulty and Barcak, 1995). Potential ribosome-binding sites (RBS) and CRP-binding sites (CRP) are indicated.…”

Section: Acknowledgmentsmentioning

confidence: 99%

“…The cAMP-CRP (cyclic-AMP receptor protein) complex helps to promote their expression and induce competence (the ability to take up and incorporate DNA) (Chandler, 1992;Redfield et al, 2005;Cameron and Redfield, 2006). Induction of competence in H. influenzae also requires the product of the tfoX (sxy) gene (Redfield, 1991;Williams et al, 1994;Zulty and Barcak, 1995;Redfield et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

“…The TfoX protein of H. influenzae itself does not seem to bind DNA, but to interact with CRP (Macfadyen, 2000;Redfield et al, 2005). Plasmids containing the tfoX gene make H. influenzae cells constitutively competent (Williams et al, 1994;Zulty and Barcak, 1995).…”

Section: Introductionmentioning

confidence: 99%

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tfoX (sxy)-dependent transformation of Aggregatibacter (Actinobacillus) actinomycetemcomitans

Bhattacharjee

Fine

Figurski

2007

Gene

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AbstracttfoX (sxy) is a regulatory gene needed to turn on competence genes. Aggregatibacter (Actinobacillus) actinomycetemcomitans has a tfoX gene that is important for transformation. We cloned this gene on an IncQ plasmid downstream of the inducible tac promoter. When this plasmid was resident in cells of A. actinomycetemcomitans and tfoX was induced, the cells became competent for transformation. Several strains of A. actinomycetemcomitans, including different serotypes, as well as rough (adherent) and isogenic smooth (nonadherent) forms were tested. Only our two serotype f strains failed to be transformed. With the other strains, we could easily get transformants with extrachromosomal plasmid DNA when closed circular, replicative plasmid carrying an uptake signal sequence (USS) was used. When a replicative plasmid carrying a USS and cloned DNA from the chromosome of A. actinomycetemcomitans was linearized by digestion with a restriction endonuclease or when genomic DNA was used directly, the outcome was allelic exchange. To facilitate allelic exchange, we constructed a suicide plasmid (pMB78) that does not replicate in A. actinomycetemcomitans and carries a region with two inverted copies of a USS. This vector gave allelic exchange in the presence of cloned and induced tfoX easily and without digestion. Using transposon insertions in cloned katA DNA, we found that as little as 78 bp of homology at one of the ends was sufficient for that end to participate in allelic exchange. The cloning and induction of tfoX makes it possible to transform nearly any strain of A. actinomycetemcomitans, and allelic exchange has proven to be important for site-directed mutagenesis.

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Section: Discussionsupporting

confidence: 86%

Section: The Tfox (Sxy) Gene Of a Actinomycetemcomitansmentioning

confidence: 82%

Section: Acknowledgmentsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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tfoX (sxy)-dependent transformation of Aggregatibacter (Actinobacillus) actinomycetemcomitans

Bhattacharjee

Fine

Figurski

2007

Gene

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Competence

Lane¹

2002

Encyclopedia of Molecular Biology

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Haemophilus

Kilian

2015

Bergey's Manual of Systematics of Archaea and Bacteria

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Hae.mo' phi.lus . Gr. n. haima blood; Gr. n. philos lover; M.L masc. Haemophilus blood‐lover. Proteobacteria / Gammaproteobacteria / Pasteurellales / Pasteurellaceae / Haemophilus Minute to medium‐sized coccobacilli or rods , generally less than 1 µm in width and variable in length, sometimes forming threads or filaments and showing marked pleomorphism . Gram negative. Nonmotile. Aerobic or facultatively anaerobic. Require preformed growth factors present in blood , particularly X factor (protoporphyrin IX or protoheme) and/or V factor (nicotinamide adenine dinucleotide [NAD] or NAD phosphate [NADP]). Even after specific growth factors have been provided, growth is best on complex media. Optimum temperature, 35–37°C. Nitrates are reduced to or beyond nitrites . Oxidase and catalase reactions vary among strains. Chemoorganotrophic. All species can attack carbohydrates fermentatively , yielding acetic, lactic, and succinic acids as end products in glucose broth. Occur as obligate parasites on the mucous membranes of humans and a variety of animal species . Several 16S rRNA sequence signatures for the family Pasteurellaceae have been demonstrated, but none of these is specific for the genus Haemophilus as presently defined (Dewhirst et al., 1992). The mol % G + C of the DNA is : 37–44. Type species : Haemophilus influenzae (Lehmann and Neumann 1896) Winslow, Broadhurst, Buchanan, Krumwiede, Rogers, and Smith 1917, 561 ( Bacterium influenzae Lehmann and Neumann 1896, 187.)

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Identification of a DNA transformation gene required for com101A+ expression and supertransformer phenotype in Haemophilus influenzae.

Cited by 44 publications

References 20 publications

tfoX (sxy)-dependent transformation of Aggregatibacter (Actinobacillus) actinomycetemcomitans

tfoX (sxy)-dependent transformation of Aggregatibacter (Actinobacillus) actinomycetemcomitans

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Haemophilus

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