Abstract:
:Population density-dependent expression of luminescence in Vibrio fischeri is controlled by the autoinducer N-3-oxohexanoyl-L-homoserine lactone (autoinducer 1 [AI-1]), which via LuxR activates transcription of the lux operon (luxICDABEG, encoding the putative autoinducer synthase [LuxI] and the luminescence enzymes). We recently identified a novel V. fischeri locus, ainS, necessary for the synthesis of a second autoinducer, N-octanoyl-L-homoserine lactone (AI-2), which via LuxR can activate lux operon transcription in the absence of AI-1. To define the regulatory role of AI-2, a luxI ainS double mutant was constructed; in contrast to the parental strain and a luxI mutant, the luxI ainS mutant exhibited no induction of luminescence and produced no detectable luminescence autoinducer, demonstrating that V. fischeri makes no luminescence autoinducers other than those whose synthesis is directed by luxI and ainS. A mutant defective only in ainS exhibited accelerated luminescence induction compared with that of the parental strain, indicating that AI-2 functions in V. fischeri to delay luminescence induction. Consistent with that observation, the exogenous addition of AI-2 inhibited induction in a dose-dependent manner in V. fischeri and Escherichia coli carrying the lux genes. AI-2 did not mediate luxR negative autoregulation, alone or in the presence of AI-1, and inhibited luminescence induction in E. coli regardless of whether luxR was under the control of its native promoter or a foreign one. Increasing amounts of AI-1 overcame the inhibitory effect of AI-2, and equal activation of luminescence required 25- to 45-fold-more AI-2 than AI-1. We conclude that AI-2 inhibits lux operon transcription. The data are consistent with a model in which AI-2 competitively inhibits the association of AI-1 with LuxR, forming a complex with LuxR which has a markedly lower lux operon-inducing specific activity than that of AI-1-LuxR. AI-2 apparently functions in V. fischeri to suppress or delay induction at low and intermediate population densities.
journal_name
J Bacterioljournal_title
Journal of bacteriologyauthors
Kuo A,Callahan SM,Dunlap PVdoi
10.1128/jb.178.4.971-976.1996subject
Has Abstractpub_date
1996-02-01 00:00:00pages
971-6issue
4eissn
0021-9193issn
1098-5530journal_volume
178pub_type
杂志文章abstract::Exponentially growing cells of the gram-negative bacterium Chromobacterium violaceum demonstrate invaginations of the cytoplasmic membrane with a high frequency. These invaginations conform to the ultrastructural appearance of mesosomes of gram-positive bacteria. As many as four mesosomes are observed per cell, each o...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.118.2.717-724.1974
更新日期:1974-05-01 00:00:00
abstract::The complex flagella of Rhizobium meliloti 2011 and MVII-1 were analyzed with regard to serology, fine structure, subunits, and amino acid composition. The serological identities of flagellar filaments of the two strains were demonstrated by double immunodiffusion with antiflagellin antiserum. The filaments had a diam...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.162.1.361-366.1985
更新日期:1985-04-01 00:00:00
abstract::The pink yeast Rhodotorula rubra of marine origin was found to be capable of extended growth at very low phosphate concentrations (K(0.5) = 10.8 nm). Average intracellular phosphate concentrations, based on isotope exchange techniques, were 15 to 200 nm, giving concentration gradients across the cell envelope of about...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.113.2.599-611.1973
更新日期:1973-02-01 00:00:00
abstract::soxR governs a superoxide response regulon that contains the genes for endonuclease IV, Mn2(+)-superoxide dismutase, and glucose 6-phosphate dehydrogenase. The soxR gene encodes a 17-kDa protein; some mutations of this gene cause constitutive overexpression of the regulon. Induction by paraquat (methyl viologen) requi...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.173.9.2864-2871.1991
更新日期:1991-05-01 00:00:00
abstract::An in vitro constructed plasmid, pVH15, consisting of the entire genome of the plasmid ColE1, the tryptophan operon of Escherichia coli, and regions of the bacteriophage PHI80pt190, spontaneously gave rise in E. coli to a mini-ColE1 plasmid consisting of approximately one-half of the ColE1 genome and a small segment o...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.126.1.447-453.1976
更新日期:1976-04-01 00:00:00
abstract::Constitutive beta-glucosidases from Saccharomyces fragilis (Y-18) and S. dobzhanskii (Y-19) precipitated at the same concentration of ammonium sulfate. The partially purified enzymes had similar activation energies, molecular weights, affinities for certain natural and synthetic beta-glucosides, and optimal pH values ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.93.1.135-141.1967
更新日期:1967-01-01 00:00:00
abstract::Spx is a global regulator that is widespread among the low-G+C-content gram-positive bacteria. Spx has been extensively studied in Bacillus subtilis, where it acts as an activator and a repressor of transcription in response to disulfide stress. Under nonstress conditions, Spx is rapidly degraded by the ClpXP protease...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.06414-11
更新日期:2012-03-01 00:00:00
abstract::The chpB locus is a chromosomal homolog of the pem locus, which is responsible for stable maintenance of plasmid R100 within the host cells. Like pem, chpB codes for two genes, chpBK and chpBI, encoding a growth inhibitor and a suppressor for the killing action of the ChpBK protein, respectively. Here, we determined t...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.176.18.5861-5863.1994
更新日期:1994-09-01 00:00:00
abstract::Pseudomonas syringae pv. tabaci 6605 possesses a genetic region involved in flagellin glycosylation. This region is composed of three open reading frames: orf1, orf2, and orf3. Our previous study revealed that orf1 and orf2 encode glycosyltransferases; on the other hand, orf3 has no role in posttranslational modificat...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00763-06
更新日期:2006-12-01 00:00:00
abstract::The EcfG-type sigma factor RpoE2 is the regulator of the general stress response in Sinorhizobium meliloti. RpoE2 activity is negatively regulated by two NepR-type anti-sigma factors (RsiA1/A2), themselves under the control of two anti-anti-sigma factors (RsiB1/B2) belonging to the PhyR family of response regulators. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01623-14
更新日期:2014-07-01 00:00:00
abstract::Doxtader, K. G. (Cornell University, Ithaca, N.Y.), and M. Alexander. Role of 3-nitropropanoic acid in nitrate formation by Aspergillus flavus. J. Bacteriol. 91:1186-1191. 1966.-Aspergillus flavus formed nitrate, 3-nitropropanoic acid (3-NPA), kojic acid, and a substance tentatively identified as N-formyl-N-hydroxy-gl...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.91.3.1186-1191.1966
更新日期:1966-03-01 00:00:00
abstract::Neisseria gonorrhoeae releases peptidoglycan fragments during growth. The majority of the fragments released are peptidoglycan monomers, molecules known to increase pathogenesis through the induction of proinflammatory cytokines and responsible for the killing of ciliated epithelial cells. In other gram-negative bacte...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01194-07
更新日期:2008-06-01 00:00:00
abstract::Expression of virulence factors by Bordetella pertussis is altered by environmental signals (antigenic modulation) and is dependent on an activator encoded by a gene called vir. We have used TnphoA (Tn5 IS50L::phoA) gene fusions to define two sets of genes whose expression is either activated (vag loci) or repressed (...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.170.11.5059-5066.1988
更新日期:1988-11-01 00:00:00
abstract::A method is described which permits the selection of mutants of Neurospora crassa that are deficient in succinic dehydrogenase activity. The method relies on the observation that succinic dehydrogenase-deficient strains fail to reduce the dye nitrotetrazolium blue when overlaid with the dye in the presence of succinat...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.137.2.900-904.1979
更新日期:1979-02-01 00:00:00
abstract::The nucleotide sequence of the agp gene, which encodes a periplasmic glucose-1-phosphatase, was determined. The deduced amino acid sequence corresponds to a 413-amino-acid-residue polypeptide with a typical hydrophobic signal sequence of 22 amino acids. The mature protein lacks the N-terminal signal peptide and has a ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.172.2.802-807.1990
更新日期:1990-02-01 00:00:00
abstract::The enterohepatic Helicobacter species Helicobacter hepaticus colonizes the murine intestinal and hepatobiliary tract and is associated with chronic intestinal inflammation, gall stone formation, hepatitis, and hepatocellular carcinoma. Thus far, the role of H. hepaticus motility and flagella in intestinal colonizatio...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00626-08
更新日期:2008-10-01 00:00:00
abstract::The Bacillus subtilis ferric uptake regulator (Fur) protein mediates the iron-dependent repression of at least 20 operons encoding approximately 40 genes. We investigated the physiological roles of Fur-regulated genes by the construction of null mutations in 14 transcription units known or predicted to function in sid...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.188.10.3664-3673.2006
更新日期:2006-05-01 00:00:00
abstract::Strains of Staphylococcus aureus, an important human pathogen, display up to 20% variability in their genome sequence, and most sequence information is available for human clinical isolates that have not been subjected to genetic analysis of virulence attributes. S. aureus strain Newman, which was also isolated from a...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01000-07
更新日期:2008-01-01 00:00:00
abstract:UNLABELLED:The σE envelope stress response is an essential signal transduction pathway which detects and removes mistargeted outer membrane (OM) β-barrel proteins (OMPs) in the periplasm of Escherichia coli It relies on σE, an alternative sigma factor encoded by the rpoE gene. Here we report a novel mutation, a nucleot...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00340-16
更新日期:2016-08-11 00:00:00
abstract::Rhizobia form a symbiotic relationship with plants of the legume family to produce nitrogen-fixing root nodules under nitrogen-limiting conditions. We have examined the importance of glutathione (GSH) during free-living growth and symbiosis of Sinorhizobium meliloti. An S. meliloti mutant strain (SmgshA) which is unab...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.187.1.168-174.2005
更新日期:2005-01-01 00:00:00
abstract::Double-stranded, 1.9-kilobase-pair (kbp) DNA molecules were found in 18 strains representing three pathogenic races of Fusarium oxysporum f. sp. conglutinans. The DNA element (pFOXC1) from a race 1 strain and the DNA element (pFOXC2) from a race 2 strain were shown by restriction endonuclease mapping to be linear. pFO...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.167.2.587-593.1986
更新日期:1986-08-01 00:00:00
abstract::A 7.5-kbp fragment of chromosomal DNA downstream of the Vibrio cholerae vibriobactin outer membrane receptor, viuA, and the vibriobactin utilization gene, viuB, was recovered from a Sau3A lambda library of O395 chromosomal DNA. By analogy with the genetic organization of the Escherichia coli enterobactin gene cluster,...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.182.6.1731-1738.2000
更新日期:2000-03-01 00:00:00
abstract::Mutants lacking an enzyme of the oxidative branch of the hexose monophosphate shunt, 6-phosphogluconolactonase (pgl), have been selected as a new class of glucose-negative derivatives of a phosphoglucose isomerase (pgi) mutant. Glucose negativity is not as complete as in mutants lacking phosphoglucose isomerase and gl...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.100.3.1296-1301.1969
更新日期:1969-12-01 00:00:00
abstract::The Escherichia coli nusA gene, nusAEc, encodes an essential protein that influences transcription elongation. Derivatives of E. coli in which the Salmonella typhimurium nusA gene, nusASt, has replaced nusAEc are viable. Thus, NusASt can substitute for NusAEc in supporting essential bacterial activities. However, hybr...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.176.5.1394-1404.1994
更新日期:1994-03-01 00:00:00
abstract::Poly-beta-hydroxybutyrate (PHB) synthesis in a cyanobacterium, Synechococcus sp. strain MA19, is controlled at the enzyme level and is dependent on the C/N balance in the culture medium. The control involves at least two enzymes. The first enzyme is PHB synthase. Little PHB synthase activity was detected in crude extr...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.179.16.5009-5013.1997
更新日期:1997-08-01 00:00:00
abstract::A pLAFR3 cosmid clone designated pVir2 containing a 25-kilobase (kb) DNA insert was isolated from a wild-type Pseudomonas solanacearum GMI1000 genomic library. This cosmid was shown to complement all but one of the nine Tn5-induced mutants which have been isolated after random mutagenesis and which have lost both path...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.169.12.5626-5632.1987
更新日期:1987-12-01 00:00:00
abstract::A novel regulatory gene, trh, which is involved in hrp gene expression, is identified in the plant pathogen Xanthomonas oryzae pv. oryzae. In the trh mutant, expression of HrpG, which is a key regulator for hrp gene expression, is reduced both under the in vitro hrp-inducing condition and in planta. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00006-06
更新日期:2006-06-01 00:00:00
abstract::The antibacterial protein toxin colicin V is secreted from Escherichia coli cells by a dedicated export system that is a member of the multicomponent ATP-binding cassette (ABC) transporter family. At least three proteins, CvaA, CvaB, and TolC, are required for secretion via this signal sequence-independent pathway. In...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.177.21.6153-6159.1995
更新日期:1995-11-01 00:00:00
abstract::The highly purified lipoprotein of the outer membrane of Escherichia coli forms paracrystals. The ultrastructures of these paracrystals were examined by electron microscopy. The needle-shaped paracrystals show several different band patterns, depending on conditions of paracrystallization. Models are presented to expl...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.127.1.564-571.1976
更新日期:1976-07-01 00:00:00
abstract::Myxococcus xanthus, a gram-negative bacterium, has a complex life cycle. In response to starvation, most cells in a population participate in the formation of multicellular aggregates (i.e., fruiting bodies) in which cells differentiate into spores. However, some cells do not enter aggregates. In this and the two acco...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.173.11.3318-3333.1991
更新日期:1991-06-01 00:00:00