Abstract:
:Recently, a new type of K+ transporter, Ktr, has been identified in the bacterium Vibrio alginolyticus (T. Nakamura, R. Yuda, T. Unemoto, and E. P. Bakker, J. Bacteriol. 180:3491-3494, 1998). The Ktr transport system consists of KtrB, an integral membrane subunit, and KtrA, a subunit peripherally bound to the cytoplasmic membrane. The genome sequence of Bacillus subtilis contains two genes for each of these subunits: yuaA (ktrA) and ykqB (ktrC) encode homologues to the V. alginolyticus KtrA protein, and yubG (ktrB) and ykrM (ktrD) encode homologues to the V. alginolyticus KtrB protein. We constructed gene disruption mutations in each of the four B. subtilis ktr genes and used this isogenic set of mutants for K+ uptake experiments. Preliminary K+ transport assays revealed that the KtrAB system has a moderate affinity with a Km value of approximately 1 mM for K+, while KtrCD has a low affinity with a Km value of approximately 10 mM for this ion. A strain defective in both KtrAB and KtrCD exhibited only a residual K+ uptake activity, demonstrating that KtrAB and KtrCD systems are the major K+ transporters of B. subtilis. Northern blot analyses revealed that ktrA and ktrB are cotranscribed as an operon, whereas ktrC and ktrD, which occupy different locations on the B. subtilis chromosome, are expressed as single transcriptional units. The amount of K+ in the environment or the salinity of the growth medium did not influence the amounts of the various ktr transcripts. A strain with a defect in KtrAB is unable to cope with a sudden osmotic upshock, and it exhibits a growth defect at elevated osmolalities which is particularly pronounced when KtrCD is also defective. In the ktrAB strain, the osmotically mediated growth defect was associated with a rapid loss of K+ ions from the cells. Under these conditions, the cells stopped synthesizing proteins but the transcription of the osmotically induced proHJ, opuA, and gsiB genes was not impaired, demonstrating that a high cytoplasmic K+ concentration is not essential for the transcriptional activation of these genes at high osmolarity. Taken together, our data suggest that K+ uptake via KtrAB and KtrCD is an important facet in the cellular defense of B. subtilis against both suddenly imposed and prolonged osmotic stress.
journal_name
J Bacterioljournal_title
Journal of bacteriologyauthors
Holtmann G,Bakker EP,Uozumi N,Bremer Edoi
10.1128/jb.185.4.1289-1298.2003keywords:
subject
Has Abstractpub_date
2003-02-01 00:00:00pages
1289-98issue
4eissn
0021-9193issn
1098-5530journal_volume
185pub_type
杂志文章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::The Mg-2+-Sarkosyl crystals (M band) procedure was used to study the effect of ribonuclease (RNase) A on the association of Escherichia coli deoxyribonucleic acid (DNA) with membrane. Incubation of gently prepared cell extracts with RNase results in the release of DNA from membrane. This effect appears to result from ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.122.2.592-598.1975
更新日期:1975-05-01 00:00:00
abstract::Staphylococcus aureus was shown to transport iron complexed to a variety of hydroxamate type siderophores, including ferrichrome, aerobactin, and desferrioxamine. An S. aureus mutant defective in the ability to transport ferric hydroxamate complexes was isolated from a Tn917-LTV1 transposon insertion library after sel...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.182.16.4394-4400.2000
更新日期:2000-08-01 00:00:00
abstract::A map location of the gluconate-6-phosphate dehydrogenase (gnd) marker was estimated in Escherichia coli C at approximately 46 min by P1 transduction. The gnd locus appears to lie between the co-transducible histidine and prophage P2 location I markers. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.116.2.1056-1058.1973
更新日期:1973-11-01 00:00:00
abstract::The polar pili of Pseudomonas aeruginosa are composed of subunits encoded by the pilA gene. Expression of pilA requires the alternative sigma factor RpoN and a pair of regulatory elements, PilS and PilR. These two proteins are members of the two-component regulatory family, in which PilS is the sensory component and P...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.178.3.831-839.1996
更新日期:1996-02-01 00:00:00
abstract::Horizontal gene transfer by conjugation plays a major role in bacterial evolution, allowing the acquisition of new traits, such as virulence and resistance to antibacterial agents. With the increased antibiotic resistance in bacterial pathogens, a better understanding of how bacteria modulate conjugation under changin...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.02279-14
更新日期:2015-03-01 00:00:00
abstract::Coat-stripped spores suspended in hypertonic solutions and supplied with two essential cations can be converted into viable protoplasts by lysozyme digestion of both cortex and germ cell wall. Calcium ions are necessary to prevent membrane rupture, and magnesium ions are necessary for changes indicative of hydration o...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.105.3.1119-1136.1971
更新日期:1971-03-01 00:00:00
abstract::A survey of chromosomal variation in the ST239 clonal group of methicillin-resistant Staphylococcus aureus (MRSA) revealed a novel genetic element, ICE6013. The element is 13,354 bp in length, excluding a 6,551-bp Tn552 insertion. ICE6013 is flanked by 3-bp direct repeats and is demarcated by 8-bp imperfect inverted r...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00352-09
更新日期:2009-10-01 00:00:00
abstract::Expression of the lower catabolic pathway of the TOL plasmid pWWO requires an aromatic acid inducer and the product of the xylS regulatory gene. Pseudomonas putida cells transformed with a plasmid containing the operator-promoter region of the lower pathway (OP2 [or Pm]), upstream from the catechol 2,3-dioxygenase str...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.170.8.3742-3746.1988
更新日期:1988-08-01 00:00:00
abstract::In Enterococcus faecalis, the site 2 protease Eep generates sex pheromones, including cAM373. Intriguingly, in Staphylococcus aureus, a peptide similar to cAM373, named cAM373_SA, is produced from the camS gene. Here, we report that the staphylococcal Eep homolog is not only responsible for the production of cAM373_SA...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00046-20
更新日期:2020-07-09 00:00:00
abstract::The formation of bacteriolytic enzymes of Staphylococcus aureus, with special reference to strain M18, was investigated under a variety of conditions. The bacteriolytic activity was tested by using whole cells of Micrococcus lysodeikticus as a substrate. Complex media were required for production, and a Casein Hydroly...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.104.1.227-233.1970
更新日期:1970-10-01 00:00:00
abstract::After the dormancy of Saccharomyces cerevisiae ascospores had been broken, the synthesis of proteins was observed first, followed rapidly by synthesis of ribonucleic acid (RNA) and much later by deoxyribonucleic acid (DNA) synthesis. Phosphoglucomutase activity increased in a periodic (step) fashion, whereas the activ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.113.3.1289-1295.1973
更新日期:1973-03-01 00:00:00
abstract::Spontaneous mutants that were resistant to zinc were isolated from Alcaligenes eutrophus CH34 containing either the native plasmid pMOL28 or a derivative derepressed for its self-transfer, pMOL50. With the cured plasmid-free derivative of CH34, strain AE104, such mutants were not detected. The mutations, which were sh...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.175.3.779-784.1993
更新日期:1993-02-01 00:00:00
abstract::A mutant of Escherichia coli lacking hydroxyethylthiazole kinase (EC 2.7.1.50) was produced by a further mutation of a temperature-sensitive, auxotrophic mutant for hydroxyethylthiazole. The parent cells possessed two distinct enzymes capable of phosphorylating hydroxyethylthiazole: one was hydroxyethylthiazole kinase...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.171.6.3228-3232.1989
更新日期:1989-06-01 00:00:00
abstract::In the yeast Saccharomyces cerevisiae, IRE1 encodes a bifunctional protein with transmembrane kinase and endoribonuclease activities. HAC1 encodes a transcription factor which has a basic leucine zipper domain. Both gene products play a crucial role in the unfolded protein response. Mutants in which one of these genes...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.183.17.4985-4993.2001
更新日期:2001-09-01 00:00:00
abstract::Xenorhabdus nematophilus, a gram-negative bacterium, is a mutualist of Steinernema carpocapsae nematodes and a pathogen of larval-stage insects. We use this organism as a model of host-microbe interactions to identify the functions bacteria require for mutualism, pathogenesis, or both. In many gram-negative bacteria, ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.183.16.4687-4693.2001
更新日期:2001-08-01 00:00:00
abstract::Strains missing several genes required for chemotaxis toward amino acids, peptides, and certain sugars were tethered and their rotational behavior was analyzed. Null strains (called gutted) were deleted for genes that code for the transducers Tsr, Tar, Tap, and Trg and for the cytoplasmic proteins CheA, CheW, CheR, Ch...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.169.5.1878-1885.1987
更新日期:1987-05-01 00:00:00
abstract::The mechanism by which iron uptake is facilitated by the siderophore rhodotorulic acid (RA) in the yeast Rhodotorula pilimanae was investigated with radioactively labeled Fe and RA and kinetically inert, chromic-substituted RA complexes. The weight of the evidence supports a model in which RA mediates iron transport t...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.136.1.69-74.1978
更新日期:1978-10-01 00:00:00
abstract::The staphylococcal virulon is activated by the density-sensing agr system, which is autoinduced by a short peptide (autoinducing peptide [AIP]) processed from a propeptide encoded by agrD. A central segment of the agr locus, consisting of the C-terminal two-thirds of AgrB (the putative processing enzyme), AgrD, and th...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.182.22.6517-6522.2000
更新日期:2000-11-01 00:00:00
abstract::Salmonella enterica serovar Typhimurium that lacks the DNA adenine methylase (Dam) ectopically expresses multiple genes that are preferentially expressed during infection, is attenuated for virulence, and confers heightened immunity in vaccinated hosts. The safety of dam mutant Salmonella vaccines was evaluated by scr...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00299-07
更新日期:2007-07-01 00:00:00
abstract::The model of pneumonia produced by intranasal inoculation of Mycoplasma pulmonis in gnotobiotic mice provided the opportunity to study the localization and identification of the infecting organisms in the tissues by immunofluorescence techniques. Frozen sections of pneumonic mouse lung were fixed in acetone, layered w...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.96.1.250-258.1968
更新日期:1968-07-01 00:00:00
abstract::The luminescence (lux) operon (luxICDABEG) of the symbiotic bacterium Vibrio fischeri is regulated by the transcriptional activator LuxR and two acyl-homoserine lactone (acyl-HSL) autoinducers (the luxI-dependent 3-oxo-hexanoyl-HSL [3-oxo-C6-HSL] and the ainS-dependent octanoyl-HSL [C8-HSL]) in a population density-re...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.182.10.2811-2822.2000
更新日期:2000-05-01 00:00:00
abstract::Novobiocin inhibited ribonculeic acid synthesis during germination of Bacillus subtilis spores. Transcription of certain kinds of genes probably required a preceding conformational change in deoxyribonucleic acid. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.142.1.366-368.1980
更新日期:1980-04-01 00:00:00
abstract::The vitamin requirements of the group Q streptococci (Streptococcus avium) and the established enterococcal species (S. faecalis and S. faecium) paralleled one another, although S. avium did not characteristically require riboflavine or pyridoxal. S. avium was further differentiated in that it required thymine for gro...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.94.2.297-299.1967
更新日期:1967-08-01 00:00:00
abstract::The thermosensitive growth phenotype exerted by runaway-mutant plasmids was suppressed by sublethal doses of the DNA gyrase inhibitors novobiocin or nalidixic acid, although the latter drug was less efficient. A novobiocin-resistant gyrB mutant Escherichia coli strain prevented expression of the runaway phenotype at 3...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.162.2.855-857.1985
更新日期:1985-05-01 00:00:00
abstract::Acinetobacter baumannii has emerged as a significant nosocomial pathogen worldwide. The increasing trend of carbapenem and fluoroquinolone resistance in A. baumannii severely limits the usage of therapeutic antimicrobial agents. Here we report the genome sequence of a multidrug-resistant A. baumannii strain, TCDC-AB07...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00244-11
更新日期:2011-05-01 00:00:00
abstract::The physiological changes in an F1-ATPase-defective mutant of Escherichia coli W1485 growing in a glucose-limited chemostat included a decreased growth yield (60%) and increased specific rates of both glucose consumption (168%) and respiration (171%). Flux analysis revealed that the mutant showed approximately twice a...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00452-06
更新日期:2006-10-01 00:00:00
abstract::We examined the kinetics of beta-galactosidase (EC 3.2.1.23) induction in the yeast Kluyveromyces lactis. Enzyme activity began to increase 10 to 15 min, about 1/10 of a cell generation, after the addition of inducer and continued to increase linearly for from 7 to 9 cell generations before reaching a maximum, some 12...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.142.3.777-785.1980
更新日期:1980-06-01 00:00:00
abstract::Deibel, R. H. (American Meat Institute Foundation, Chicago, Ill.). Hydrolysis of proteins and nucleic acids by Lancefield group A and other streptococci. J. Bacteriol. 86:1270-1274. 1963.-Classically, group A streptococci have been considered to be nonproteolytic in spite of the observation that a proteinase is produc...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.86.6.1270-1274.1963
更新日期:1963-12-01 00:00:00
abstract::A new class II (Tn3-like) transposable element, designated Tn5401, was recovered from a sporulation-deficient variant of Bacillus thuringiensis subsp. morrisoni EG2158 following its insertion into a recombinant plasmid. Sequence analysis of the insert revealed a 4,837-bp transposon with two large open reading frames, ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.176.10.2835-2845.1994
更新日期:1994-05-01 00:00:00