A new Vibrio fischeri lux gene precedes a bidirectional termination site for the lux operon

Swartzman, Alexandra; Kapoor, Sanjay; Graham, Angus; Meighen, Edward A.

doi:10.1128/jb.172.12.6797-6802.1990

Cited by 65 publications

(36 citation statements)

References 27 publications

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“…Downstream of ainS is another gene, ainR, which shows similarity to luxN, a gene similarly located in V. harveyi. LuxN is believed to possess both the sensor kinase and response regulator functions for the response to acyl-HSL signal [57]. By analogy, the possible interaction between Cg-HSL and AinR is intriguing [25].…”

Section: Dunlap Unpublished Data)mentioning

confidence: 99%

“…The search for additional bacteria that use autoinducers as signal molecules has been accelerated by the use of biological assays that allow the user to test the cell-free supernatant of "conditioned" media for their presence. These systems take advantage of luminescence or reporter constructs and the low substrate specificity of some LuxR homologs [57,59,60].…”

Section: The Use Of Acyl Homoserine Lactone Signals By Other Bacteriamentioning

confidence: 99%

“…In that year it was reported that both Pseudomonas aeruginosa, an opportunistic pathogen in humans that is also found in soil and water, and the plant pathogen Agrobacterium tumefaciens use autoinducer molecules in combination with LuxR-type proteins to regulate virulence gene expression [55][56][57]. Since that time, more than 25 species of bacteria have been found to use acyl homoserine lactones and homo logs of LuxR to coordinate gene expression with population density [2,58].…”

Section: The Use Of Acyl Homoserine Lactone Signals By Other Bacteriamentioning

confidence: 99%

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The quorum-sensing regulation of Vibrio fischeri : novel components of the autoinducer/LuxR regulatory circuit

Callahan¹

1999

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In the marine bacterium Vibrio fischeri two intercellular homoserine-Iactone signal molecules (luxI-dependent 30C 6 -HSL and the ainS-dependent Cs-HSL) and the transcriptional activator LuxR regulate the luminescence system in a cell-density dependent manner by a process termed quorum sensing. In this study, five additional proteins whose production is regulated by quorum sensing are described, and the genes encoding four of the five proteins, denoted as QsrP, RibB, QsrV, and AcfA, are analyzed. Each protein is positively regulated by 30C 6 -HSL and LuxR and negatively regulated at low population density by Cs-HSL. Probable LuxRlautoinducer binding sites are found in the promoter region of each. QsrP and RibB are encoded monocistronically, whereas AcfA and QsrV appear to be encoded by a two-gene operon. On the basis of sequence similarity to proteins of known function from other organisms, RibB is believed to be an enzyme that catalyzes the transformation of ribulose 5-phosphate to 3,4-dihydroxy-2-butanone 4-phosphate, a precursor for the xylene ring of riboflavin; AcfA is believed to be a pilus subunit; and the functions of QsrP and QsrV are unknown at this time. A qsrP mutant was reduced in its ability to colonize its symbiotic partner, Euprymna scolopes when placed in competition with the parent strain. On the other hand, a mutant strain of V. fischeri containing an insertion in acfA, which is believed to be polar with respect to qsrV, displayed enhanced colonization competence in a competition assay. A ribB mutant grew well on media not supplemented with additional riboflavin and displayed normal induction of luminescence. Both phenotypes suggest that the lack of a functional ribB gene is complemented by another gene of similar function in the mutant. Oriented divergently from acfA are open reading frames that code for two putative proteins that are similar in sequence to members of the LysR family of transcriptional regulators. Organization of the two divergent sets of genes and the shared promoter region suggests that transcription of acfA and qsrV may be regulated by one or both of these divergently transcribed proteins. This work defines a quorum-sensing regulon in V. fischeri. A model describing its regulation is presented.2

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Section: Dunlap Unpublished Data)mentioning

confidence: 99%

Section: The Use Of Acyl Homoserine Lactone Signals By Other Bacteriamentioning

confidence: 99%

Section: The Use Of Acyl Homoserine Lactone Signals By Other Bacteriamentioning

confidence: 99%

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The quorum-sensing regulation of Vibrio fischeri : novel components of the autoinducer/LuxR regulatory circuit

Callahan¹

1999

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“…In certain Photobactenium species, an additional gene (luxF), homologous in sequence to the luciferase genes, is also present (1,12,23). A new gene, luxG, closely linked to luxE, has been discovered in Vibrio and Photobacterium species (14,24,25). The order of the lux genes in these species is luxCDAB(F)EG, with the luciferase genes flanked by the luxCD and luxE genes.…”

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confidence: 99%

Multiple repetitive elements and organization of the lux operons of luminescent terrestrial bacteria

Meighen

Szittner

1992

J Bacteriol

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The complete nucleotide sequences of the luxt4 to luxE genes, as well as the flanking regions, were determined for the ux operons of two Xenorhabdus luminescens strains isolated from insects and humans. The nucleotide sequences of the corresponding Xx genes (luxCDABE) were 85 to 90%o identical but completely diverged 350 bp upstream of the first lux gene (hlxC) and immediately downstream of the last lux gene (luxE). These results show that the IuxG gene found immediately downstream of luxE in luminescent marine bacteria is missing at this location in terrestrial bacteria and raise the possibility that the lux operons are at different positions in the genomes of the X. luminescens strains. Four enteric repetitive intergenic consensus (ERIC) or intergenic repetitive unit (IRU) sequences of 126 bp were identified in the 7.7-kbp DNA fragment from theX. luminescens strain isolated from humans, providing the first example of multiple ERIC structures in the same operon including two ERIC structures at the same site. Only a single ERIC structure between luxB and luxE is present in the 7-kbp hlx DNA from insects. Analysis of the genomic DNAs from five X. luminescens strains or isolates by polymerase chain reaction has demonstrated that an ERIC structure is between luxB and lhrE in all of the strains, whereas only the strains isolated from humans had an ERIC structure between luxD and lux4. The results indicate that there has been insertion and/or deletion of multiple 126-bp repetitive elements in the lux operons ofX. luminescens during evolution.

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“…Autoinducer (N-3-oxohexanoyl-L-homoserine lactone [N-3-oxohexanoyl-L-HSL]) is a self-produced, membrane-permeable compound that accumulates as V fischeri population density increases (10,20). At threshold concentrations, autoinducer, via the autoinducer receptor and transcriptional activator LuxR, triggers transcription of the luminescence (lux) operon, luxICDABEG, which contains genes for autoinducer synthase (luxr) and luminescence enzymes (13,14,30).…”

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confidence: 99%

Mutant analysis of luminescence and autoinduction in a marine bacterium

Kuo¹

1994

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The marine symbiotic bacterium Vibriofischeri is striking for its ability both to emit light and to dramatically regulate light emission using a cell-to-cell signalling mechanism called autoinduction.The latter is mediated by a signal molecule called the "autoinducer". The mechanistic bases of both luminescence and autoinduction are well known in V. fischeri, but this knowledge is mostly derived from studies of the cloned luminescence and autoinduction genes expressed in Escherichia coli. In this study, luminescence and autoinduction mutations were systematically generated in V. fischeri to explore aspects of luminescence and autoinduction not addressable in E. coli, such as the adaptive significance of luminescence. Most dramatically, the mutants revealed the presence of multiple autoinducers and autoinducer synthases in V. fischeri. One of the autoinducers (autoinducer-2, or AI-2) was chemically purified and shown to be Noctanoyl-L-homoserine lactone. The genetic locus encoding the AI-2 synthase was cloned and designated ain (autoinducer). Manipulation of ain and AI-2 in V. fischeri demonstrated that the function of AI-2 appears to be to inhibit rather than to promote autoinduction. 2 ACKNOWLEDGMENTS

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A new Vibrio fischeri lux gene precedes a bidirectional termination site for the lux operon

Cited by 65 publications

References 27 publications

The quorum-sensing regulation of Vibrio fischeri : novel components of the autoinducer/LuxR regulatory circuit

The quorum-sensing regulation of Vibrio fischeri : novel components of the autoinducer/LuxR regulatory circuit

Multiple repetitive elements and organization of the lux operons of luminescent terrestrial bacteria

Mutant analysis of luminescence and autoinduction in a marine bacterium

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