Abstract:
:We have developed a general method for determining whether a gene of Escherichia coli is essential for viability. The method requires cloned DNA spanning the gene in question and a reasonably detailed genetic and physical map of the cloned segment. Using this information, one constructs a deletion of the target gene in vitro. For convenience, the deletion can be marked by an antibiotic resistance gene. A DNA segment containing the deletion is then cloned onto an att delta phage lambda vector. Integration of this phage, by homologous recombination at the target locus, and subsequent excision provide an efficient route for crossing the marked deletion onto the bacterial chromosome. Failure to delete the target gene indicates either that the resulting deletion was not viable or that the desired recombinational event did not take place. The use of prophage excision to generate the deletion allows one to estimate the fraction of deletion-producing events by analysis of the other product of the excision, the phage produced on induction of the prophage. In this way one can determine whether failure to recover a particular chromosomal deletion was due to its never having been formed, or, once formed, to its failure to survive. Applying this method to the polA gene, we found that polA is required for growth on rich medium but not on minimal medium. We repeated the experiment in the presence of plasmids carrying functional fragments of the polA gene, corresponding to the 5'-3' exonuclease and the polymerase-3'-5' exonuclease portions of DNA polymerase I. Surprisingly, either of these fragments, in the absence of the other, was sufficient to allow growth on rich medium.
journal_name
J Bacterioljournal_title
Journal of bacteriologyauthors
Joyce CM,Grindley NDdoi
10.1128/JB.158.2.636-643.1984subject
Has Abstractpub_date
1984-05-01 00:00:00pages
636-43issue
2eissn
0021-9193issn
1098-5530journal_volume
158pub_type
杂志文章abstract::Rhodobacter sphaeroides is a free-living, photoheterotrophic bacterium known for its genomic and metabolic complexity. We have discovered that this purple photosynthetic organism possesses a quorum-sensing system. Quorum sensing occurs in a number of eukaryotic host-associated gram-negative bacteria. In these bacteria...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.179.23.7530-7537.1997
更新日期:1997-12-01 00:00:00
abstract::Isolated sheaths of Leptothrix discophora SP-6 (ATCC 51168) were tested for susceptibility to degradation by a variety of chemical denaturants and lytic enzymes and found to be resistant to many reagents and enzyme treatments. However, disulfide bond-reducing agents such as dithiothreitol (DTT), beta-mercaptoethanol, ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.175.24.7819-7827.1993
更新日期:1993-12-01 00:00:00
abstract::The importance of the physiological state of a culture of Saccharomyces cerevisiae for tolerance to sudden osmotic dehydration was studied, and it was investigated whether specific osmotolerance factors were demonstrable. The microcalorimeter was used to monitor growth, and different physiological states of the cultur...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.170.10.4562-4568.1988
更新日期:1988-10-01 00:00:00
abstract::In Pseudomonas aeruginosa, flagellar genes are regulated in a cascade headed by FleQ, an NtrC/NifA-type activator. FleQ and RpoN positively regulate expression of flhA, fliE, fliL, and fleSR genes, among others. Direct interaction of FleQ with flhA, fliE, fliL, and fleSR promoters was demonstrated by gel shift assay, ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.184.19.5251-5260.2002
更新日期:2002-10-01 00:00:00
abstract::In Escherichia coli, T:G mismatches in specific contexts are corrected by a very short patch (VSP) repair system. Previous studies have shown that the product of gene vsr mediates correction of T:G to C:G in the 5'CTAGG/3'GGTCC context and in some related contexts. Amber mutations that arose in CAG sequences in gene c...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.177.3.660-666.1995
更新日期:1995-02-01 00:00:00
abstract::Segregation was studied by measuring the positions of autoradiographic grain clusters in chains formed from single cells containing on average less than one radiolabeled chromosome strand. The degree to which chromosomal and cell wall material cosegregated was quantified by using the methods of S. Cooper and M. Weinbe...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.171.1.349-352.1989
更新日期:1989-01-01 00:00:00
abstract::The bacterial response to stress is controlled by two proteins, RelA and SpoT. RelA generates the alarmone (p)ppGpp under amino acid starvation, whereas SpoT is responsible for (p)ppGpp hydrolysis and for synthesis of (p)ppGpp under a variety of cellular stress conditions. It is widely accepted that RelA is associated...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00315-07
更新日期:2007-09-01 00:00:00
abstract::The SasG surface protein of Staphylococcus aureus has been shown to promote the formation of biofilm. SasG comprises an N-terminal A domain and repeated B domains. Here we demonstrate that SasG is involved in the accumulation phase of biofilm, a process that requires a physiological concentration of Zn(2+). The B doma...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00628-10
更新日期:2010-11-01 00:00:00
abstract::The global regulatory protein Crc is involved in the repression of several catabolic pathways for sugars, hydrocarbons, and nitrogenated and aromatic compounds in Pseudomonas putida and Pseudomonas aeruginosa when other preferred carbon sources are present in the culture medium (catabolite repression), therefore modul...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.187.11.3678-3686.2005
更新日期:2005-06-01 00:00:00
abstract::Protein glycosylation is an important posttranslational modification that occurs in all domains of life. Pilins, the structural components of type IV pili, are O glycosylated in Neisseria meningitidis, Neisseria gonorrhoeae, and some strains of Pseudomonas aeruginosa. In this work, we characterized the P. aeruginosa 1...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01318-07
更新日期:2007-11-01 00:00:00
abstract::Myxococcus xanthus multicellular fruiting body development is initiated by nutrient limitation at high cell density. Five clustered point mutations (sasB5, -14, -15, -16, and -17) can bypass the starvation and high-cell-density requirements for expression of the 4521 developmental reporter gene. These mutants express ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:
更新日期:1998-12-01 00:00:00
abstract::The chromatophores of Chromatium vinosum, as well as six other photosynthetic bacteria, contained two or more proteins which were insoluble when heated in the presence of sodium dodecyl sulfate (SDS) and 2-mercaptoethanol (beta-ME). When the chromatophores were dissolved at room temperature in SDS-beta-ME, these prote...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.138.1.207-217.1979
更新日期:1979-04-01 00:00:00
abstract::Cnm is a surface-associated protein present in a subset of Streptococcus mutans strains that mediates binding to extracellular matrices, intracellular invasion, and virulence. Here, we showed that cnm transcription is controlled by the global regulators CovR and VicRKX. In silico analysis identified multiple putative ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00141-18
更新日期:2018-11-06 00:00:00
abstract::Membrane vesicles containing internal alcohol dehydrogenase and nicotinamide adenine dinucleotide (NAD) were prepared from Escherichia coli ML308-225. Upon the addition of ethanol, these vesicles respired and transported several amino acids. Transport rates driven by internally generated reduced NAD (NADH) were about ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.120.2.861-865.1974
更新日期:1974-11-01 00:00:00
abstract::The morphology of nucleoids and mesosomes of Bacillus subtilis in stationary-and lag-phase cultures was studied by making three-dimensional cell reconstructions in plastic of electron micrographs of serial sections. In cells from stationary cultures, the dormant nucleoids are frequently, but not always, spherical and ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.121.3.1189-1199.1975
更新日期:1975-03-01 00:00:00
abstract::We investigated an osmotic remedial mutant of Saccharomyces which was deficient in galactose-1-phosphate uridyl transferase. Both the rate of growth and the transferase activity of the mutant culture were dependent on the osmotic activity of the growth medium. Organic and ionic solutes proved to be equally effective i...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.95.3.1103-1110.1968
更新日期:1968-03-01 00:00:00
abstract::Cyanothece sp. strain ATCC 51142 is a unicellular, diazotrophic cyanobacterium which demonstrated extensive metabolic periodicities of photosynthesis, respiration, and nitrogen fixation when grown under N2-fixing conditions. N2 fixation and respiration peaked at 24-h intervals early in the dark or subjective-dark peri...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.179.13.4319-4327.1997
更新日期:1997-07-01 00:00:00
abstract::An IMP dehydrogenase gene was isolated from Candida albicans on a approximately 2.9-kb XbaI genomic DNA fragment. The putative Candida IMP dehydrogenase gene (IMH3) encodes a protein of 521 amino acids with extensive sequence similarity to the IMP dehydrogenases of Saccharomyces cerevisiae and various other organisms....
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.179.7.2331-2338.1997
更新日期:1997-04-01 00:00:00
abstract::Genome sequences from the prolific Roseobacter clade in the Alphaproteobacteria are beginning to reveal the genetic basis for the diverse lifestyles of these organisms. Here we present the genome sequences of Oceanicola granulosus HTCC2516(T) and Oceanicola batsensis HTCC2597(T), two marine Roseobacter species isolate...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00412-10
更新日期:2010-07-01 00:00:00
abstract::Neisseria meningitidis serogroup B strain M986 was examined for the involvement of lipid intermediate(s) participating in the biosynthesis of the sialic acid capsular polysaccharide. The addition of exogenous undecaprenyl phosphate, phosphatidylethanolamine, or phosphatidylglycerol to particulate membranes, in the pre...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.161.3.861-867.1985
更新日期:1985-03-01 00:00:00
abstract::The highly defective rho-15 mutant of Escherichia coli produces plasmid DNA that is 22% less negatively supercoiled than DNA from an isogenic wild-type strain (J. S. Fassler, G. F. Arnold, and I. Tessman, Mol. Gen. Genet. 204:424-429, 1986). We extended our measurements of plasmid superhelicity to additional rho mutan...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.170.9.4266-4271.1988
更新日期:1988-09-01 00:00:00
abstract::The location of the Escherichia coli K-12 genes determining or regulating glutamate transport, and the location of the gene determining glutamate decarboxylase synthesis, were established by conjugation. The ability to grow on glutamate as the sole source of carbon and energy was used to select for glutamate transport...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.93.4.1409-1415.1967
更新日期:1967-04-01 00:00:00
abstract::Chimeric plasmids, which were useful as cloning vehicles in a Streptococcus sanguis (Challis) host vector system, have been constructed. By using three different strategies of restriction endonuclease digestion and ligation, a deoxyribonucleic acid (DNA) fragment bearing an erythromycin resistance determinant was liga...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.143.3.1425-1435.1980
更新日期:1980-09-01 00:00:00
abstract::Oxalurate, the gratuitous inducer of the allantoin degradative enzymes, was taken into the cell by an energy-dependent active transport system with an apparent Km of 1.2 mM. Efflux of previously accumulated oxalurate was rapid, with a half-life of about 2 min. The oxalurate uptake system appears to be both constitutiv...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.139.3.917-923.1979
更新日期:1979-09-01 00:00:00
abstract::At early stages of sporulation, the spoIIA locus is transcribed as a tricistronic (1.7-kb) operon, coding for sigma F and for two proteins that modulate the activity of sigma F. The locus is transcribed as a longer (2.9-kb) transcript at the late stages of sporulation. We show here that the longer transcript contains ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.174.15.4885-4892.1992
更新日期:1992-08-01 00:00:00
abstract::Human-pathogenic Bartonella henselae causes cat scratch disease and vasculoproliferative disorders. An important pathogenicity factor of B. henselae is the trimeric autotransporter adhesin (TAA) Bartonella adhesin A (BadA), which is modularly constructed, consisting of a head, a long and repetitive neck-stalk module, ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01461-13
更新日期:2014-06-01 00:00:00
abstract::Quorum sensing of Sinorhizobium meliloti relies on N-acyl-homoserine lactones (AHLs) as autoinducers. AHL production increases at high population density, and this depends on the AHL synthase SinI and two transcriptional regulators, SinR and ExpR. Our study demonstrates that ectopic expression of the gene rne, coding ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01471-13
更新日期:2014-04-01 00:00:00
abstract::Microarray studies of the Escherichia coli response to nitric oxide and nitrosative stress have suggested that additional transcriptional regulators of this response remain to be characterized. We identify here the product of the yjeB gene as a negative regulator of the transcription of the ytfE, hmpA and ygbA genes, ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.188.3.874-881.2006
更新日期:2006-02-01 00:00:00
abstract::We investigated the effect of time, temperature, and the presence of sodium chloride, nitrates, and nitrites in the medium on the growth and production of enterotoxin B by Staphylococcus aureus. Assays by the double gel-diffusion method showed that maximal enterotoxin B production occurs at the beginning of the statio...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.95.4.1207-1211.1968
更新日期:1968-04-01 00:00:00
abstract::Evolution by natural selection occurs in cultures of Escherichia coli maintained under carbon starvation stress. Mutants of increased fitness express a growth advantage in stationary phase (GASP) phenotype, enabling them to grow and displace the parent as the majority population. The first GASP mutation was identified...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.182.15.4361-4365.2000
更新日期:2000-08-01 00:00:00