Locus of the Pseudomonas aeruginosa toxin A gene

Hanne, Larry F.; Howe, Timothy R.; Iglewski, Barbara H.

doi:10.1128/jb.154.1.383-386.1983

Cited by 31 publications

(12 citation statements)

References 33 publications

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“…and 3083-2 chromosomes is his tox trp vct met (13,14), the CT structural genes are separated from tox by at least one gene that is not directly related to CT synthesis, i.e., trp. A similar observation has recently been reported for toxin A produced by many Pseudomonas aeruginosa isolates (4). The position of the toxin A structural gene on the P. aeruginosa PAO genetic map was found to be approximately 45 min away from a gene that apparently regulates production of toxin A.…”

supporting

confidence: 85%

Evidence indicating that the cholera toxin structural genes of Vibrio cholerae RJ1 and 3083-2 are between met and trp

Saunders¹,

Kubala²,

Vaidya³

et al. 1983

Infect Immun

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An enterotoxin A subunit-specific radioactive probe was used to correlate expression of vct-1 or vct-2 with the presence of specific restriction fragments in the DNAs of several wild-type and recombinant Vibrio cholerae strains. The data are consistent with the conclusion that vct is a cholera toxin structural gene. We previously reported that the gene vct specifies the antigenic structure of cholera toxin (CT) and is located between met and trp on the Vibrio cholerae genetic map (14). The vet-I

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supporting

confidence: 85%

Evidence indicating that the cholera toxin structural genes of Vibrio cholerae RJ1 and 3083-2 are between met and trp

Saunders¹,

Kubala²,

Vaidya³

et al. 1983

Infect Immun

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“…This study has demonstrated that the genes for regulation of formation and release of extracellular proteins in P. aeruginosa were located in different parts of the chromosome but not in the region of the chromosome in which the structural genes for elastase and exotoxin A were found (80'to-85' region [12,16]), There were indications of clustering of xcp genes in certain areas, such as 35' (xcp-2, xcp-31xcp-31); 40' (xcp4, xcp41-xcp45); and 55' (xcp-5, xcp-S1, xcp-52, xcp-53). Analysis of the phenotype properties of the strains showed that the mutations caused pleiotropic effects and revealed two distinct classes of mutants, tentatively designated class I and class II.…”

Section: Discussionmentioning

confidence: 90%

Genetic mapping and characterization of Pseudomonas aeruginosa mutants defective in the formation of extracellular proteins

Wretlind¹,

Pavlovskis²

1984

J Bacteriol

102

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We isolated 15 mutants of Pseudomonas aeruginosa PAO which were defective in the formation of certain extracellular proteins, such as elastase, staphylolytic enzyme, and lipase (Xcp mutants). The mutations were mapped on the chromosome by conjugation and transduction. The locations were xcp-J near 0', with the gene order cys-59-xcp-1-proB, and loci xcp-2, xcp-3, and xcp-31 at 35', with the gene order trpC,D-xcp-31xcp-31-xcp-2-argC. Loci xcp4 and xcp41 through xcp44 were cotransducible with proA at 40'; loci xcp-5, xcp-51, xcp-52, and xcp53 were located at 55', with the gene order leu-10-trpF-met-9010xcp-53-xcp-51xcp-511xcp-52, and xcp-6 was located at 65' to 70', between catA and mtu-9002. Nine mutations (xcp-2, xcp-3, xcp-31, xcp4, and xcp4J through xcp45) caused decreased production of extracellular enzymes. Six strains with mutations xcp-1, xcp-5, xcp-51, xcp-52, xcp-53, and xcp-6 produced cell-bound exoproteins and had defective release mechanisms. The regulation of production of alkaline phosphatase and phospholipase C is different from other exoproteins, such as elastase, but they all seem to share a common release mechanism. Alkaline protease had separate mechanisms for regulation and release, since this protease was found in culture supernatants of all but one of the mutants, and none of the strains had cell-bound enzyme. The formation and release of extracellular enzymes has been studied mostly in gram-positive bacteria such as Bacillus spp. (6), but there is comparatively little information about gram-negative organisms in this respect. Pseudomonas aeruginosa produces several extracellular enzymes and toxins, and some of these proteins are of importance in the pathogenicity of Pseudomonas infections (25, 34). Most strains produce at least two proteases, designated elastase and alkaline protease (29-31). Lipase, staphylolytic enzyme, alkaline phosphatase, and phospholipase C are also found extracellularly in broth media (7, 47, 48). Exotoxin A is a ribosylating enzyme which inactivates the ribosomal protein EF-2 in eucaryotic cells (17). Previous studies with protease-deficient mutants of P. aeruginosa PAKS-1 showed (48) that the mutations caused pleiotropic effects with decreased activities of several extracellular enzymes; i.e., they were exoprotein deficient. Differences in phenotypic properties between mutants indicated that a number of genetic loci were involved. This study on exoprotein-deficient Pseudomonas mutants was undertaken to determine the location of chromosomal * Corresponding author.

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“…The tox-2 mutant produces 100-fold less toxin yet still maintains parental levels of protease and total extracellular protein. Since this tox-2 locus is well separated from the toxin structural gene of PA01 (toxA-1) at 85 min, as determined by Hanne et al (10), it has been suggested that the expression of the toxin-encoding gene is positively regulated by the gene product of the tox-2 locus. Gray et al (8) recently cloned the exotoxin A structural gene into Escherichia coli but expression of toxin could not be detected without placing the gene under the control of E. coli transcriptional/translational signals.…”

mentioning

confidence: 89%

“…Identical in mode of action to diphtheria toxin, exotoxin A catalyzes the transfer of the ADP-ribosyl moiety of NAD onto elongation factor 2, thereby inhibiting protein synthesis in eucaryotic cells (15,16). Exotoxin A is chromosomally encoded (10) and is produced by most (>90%) P. aeruginosa strains (4).…”

mentioning

confidence: 99%

Cloning of a gene involved in regulation of exotoxin A expression in Pseudomonas aeruginosa

Hedstrom¹,

Funk²,

Kaper³

et al. 1986

Infect Immun

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We have cloned a gene from Pseudomonas aeruginosa that stimulates the expression of exotoxin A. A recombinant library of genomic DNA from strain PA103 constructed with a broad-host-range plasmid vector containing chromosomal insert fragments generated by Sau3A was used to transform the hypotoxigenic mutant strain PA103-29. A recombinant plasmid, pFHK6, was isolated from a PA103-29 transformant which displayed increased toxin production. From pFHK6, which contained a 20-kilobase-pair chromosomal insert, a 3-kilobase-pair XhoI fragment was isolated and subcloned into the plasmid cloning vector pVK101 to give pFHK10. In toxigenic P. aeruginosa strains containing pFHK10, toxin expression was increased 10-fold and high levels of iron in the culture medium only partially inhibited the overproduction. Expression studies suggested that pFHK10 did not contain the toxin structural gene. In addition, Southern analysis with the 3-kilobase-pair XhoI fragment suggested that the putative toxin regulatory gene is common among different strains of P. aeruginosa including previously reported nontoxigenic strains.

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Locus of the Pseudomonas aeruginosa toxin A gene

Cited by 31 publications

References 33 publications

Evidence indicating that the cholera toxin structural genes of Vibrio cholerae RJ1 and 3083-2 are between met and trp

Evidence indicating that the cholera toxin structural genes of Vibrio cholerae RJ1 and 3083-2 are between met and trp

Genetic mapping and characterization of Pseudomonas aeruginosa mutants defective in the formation of extracellular proteins

Cloning of a gene involved in regulation of exotoxin A expression in Pseudomonas aeruginosa

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