Abstract:
:For Escherichia coli, growth on acetate requires the induction of the enzymes of the glyoxylate bypass, isocitrate lyase and malate synthase. The branch point between the glyoxylate bypass and the Krebs cycle is controlled by phosphorylation of isocitrate dehydrogenase (IDH), inhibiting that enzyme's activity and thus forcing isocitrate through the bypass. This phosphorylation cycle is catalyzed by a bifunctional enzyme, IDH kinase/phosphatase, which is encoded by aceK. We have employed random mutagenesis to isolate novel alleles of aceK. These alleles were detected by the loss of ability to complement an aceK null mutation. The products of one class of these alleles retain IDH kinase activity but have suffered reductions in IDH phosphatase activity by factors of 200 to 400. Selective loss of the phosphatase activity also appears to have occurred in vivo, since cells expressing these alleles exhibit phenotypes which are reminiscent of strains lacking IDH; these strains are auxotrophic for glutamate. Assays of cell-free extracts confirmed that this phenotype resulted from nearly quantitative phosphorylation of IDH. The availability of these novel alleles of aceK allowed us to assess the significance of the precise control which is a characteristic of the IDH phosphorylation cycle in vivo. The fractional phosphorylation of IDH was varied by controlled expression of one of the mutant alleles, aceK3, in a wild-type strain. Reduction of IDH activity to 50% of the wild-type level did not adversely affect growth on acetate. However, further reductions inhibited growth, and growth arrest occurred when the IDH activity fell to 15% of the wild-type level. Thus, although wild-type cells maintain a precise effective IDH activity during growth on acetate, this precision is not critical.
journal_name
J Bacterioljournal_title
Journal of bacteriologyauthors
Ikeda T,LaPorte DCdoi
10.1128/jb.173.5.1801-1806.1991subject
Has Abstractpub_date
1991-03-01 00:00:00pages
1801-6issue
5eissn
0021-9193issn
1098-5530journal_volume
173pub_type
杂志文章abstract::The ompB operon of Escherichia coli contains the structural genes for two proteins, OmpR and EnvZ, which control the osmoregulated biosynthesis of the porin proteins OmpF and OmpC. By inserting XbaI octamer linkers into the cloned ompB locus, four distinct frameshift mutants were isolated and subsequently characterize...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.164.2.578-584.1985
更新日期:1985-11-01 00:00:00
abstract::Fifteen low-temperature conditional division mutants of Escherichia coli K-12 was isolated. They grew normally at 39 degrees C but formed filaments at 30 degrees C. All exhibited a coordinated burst of cell division when the filaments were shifted to the permissive temperature (39 degrees C). None of the various agent...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.133.1.256-264.1978
更新日期:1978-01-01 00:00:00
abstract::The polycistronic mRNA encoding the nine genes of the unc operon of Escherichia coli was studied. We demonstrated the ribosome-binding capabilities of six of the nine unc genes, uncB, uncE, uncF, uncH, uncA, and uncD, by using the technique of primer extension inhibition or "toeprinting." No toeprint was detected for ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.171.7.3901-3908.1989
更新日期:1989-07-01 00:00:00
abstract::Bacillus subtilis cwlD and dacB mutants produce spore peptidoglycan (PG) with increased cross-linking but with little change in spore core hydration compared to the wild type. A cwlD dacB double mutant produced spores with a two- to fourfold greater increase in PG cross-linking and novel muropeptides containing glycin...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.181.19.6205-6209.1999
更新日期:1999-10-01 00:00:00
abstract::A histidine kinase protein (Cph1) with sequence homology and spectral characteristics very similar to those of the plant phytochrome has been recently identified in the cyanobacterium Synechocystis sp. strain PCC 6803. Cph1 together with Rcp1 (a protein homologue to the response regulator CheY) forms a light-regulated...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.182.1.38-44.2000
更新日期:2000-01-01 00:00:00
abstract::A mutant of Escherichia coli K-12 was examined which has growth medium-dependent lysyl-transfer ribonucleic acid (tRNA) ligase activity. In minimal medium or 0.5% yeast extract, the activity of the enzyme in the mutant strain was 5 to 10% of wild type. However, when the mutant was grown in a highly enriched medium, su...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.113.1.167-177.1973
更新日期:1973-01-01 00:00:00
abstract::Cell division of Escherichia coli K-12 strain PA3092 was inhibited by the addition of adenosine 3',5'-phosphate (cAMP), and the cellular morphology was changed from rods into filaments. Nucleoids in the filaments were regularly distributed and septum formation was perfectly inhibited. This inhibition of cell division ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.147.3.1105-1109.1981
更新日期:1981-09-01 00:00:00
abstract::During the growth of Clostridium cellulolyticum in chemostat cultures with ammonia as the growth-limiting nutrient, as much as 30% of the original cellobiose consumed by C. cellulolyticum was converted to cellotriose, glycogen, and polysaccharides regardless of the specific growth rates. Whereas the specific consumpti...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.182.7.2010-2017.2000
更新日期:2000-04-01 00:00:00
abstract::The distribution of a pulse of teichoic acid-specific radiolabel between wall and membrane teichoic acids in pneumococci was constant over a subsequent chase period, suggesting that wall and membrane teichoic acids are biosynthesized simultaneously and independently. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.122.1.335-337.1975
更新日期:1975-04-01 00:00:00
abstract::The leucine auxotroph Escherichia coli 2961 exhibited stringent control of net ribonucleic acid (RNA) synthesis during amino acid starvation. After leucine was exhausted from the medium, the rate of uracil incorporation into RNA rapidly decreased to 2 to 4% of the prestarvation value. Infection of the starved cells wi...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.96.1.111-116.1968
更新日期:1968-07-01 00:00:00
abstract::The synthesis of cytosine deaminase in Salmonella typhimurium is repressed by pyrimidines. This repression is mediated by both a uridine and a cytidine compound, indicating a distinct difference in the regulation of synthesis of cytosine deaminase from the regulation of the de novo pyrimidine pathway enzymes. A salvag...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.149.3.1171-1174.1982
更新日期:1982-03-01 00:00:00
abstract::Cultures of recombination-deficient strains of Escherichia coli are composed of three classes of cells: (i) viable cells, which can undergo 20 or more generations, (ii) residually dividing cells, which can undergo fewer than 20 generations (probably an average of fewer than 6), and (iii) nondividing cells, which are i...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.118.1.242-249.1974
更新日期:1974-04-01 00:00:00
abstract::Outer membrane alterations were characterized in spontaneous mutants of the Erwinia chrysanthemi 3937jRH, which were selected for resistance to bacteriophage phi EC2. All but one of the mutants analyzed were affected in their lipopolysaccharide (LPS) structure, lacking the entire heterogeneous region of apparent high ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.169.9.4011-4017.1987
更新日期:1987-09-01 00:00:00
abstract::Methanococcus aeolicus, Methanococcus maripaludis, and Methanococcus voltae contain similar levels of four enzymes of branched-chain amino acid biosynthesis: acetohydroxy acid synthase, acetohydroxy acid isomeroreductase, dihydroxy acid dehydratase, and transaminase B. Following growth at low partial pressures of H2-C...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.173.6.2086-2092.1991
更新日期:1991-03-01 00:00:00
abstract::In Zymomonas mobilis, three- to fourfold more glyceraldehyde-3-phosphate dehydrogenase protein than phosphoglycerate kinase is needed for glycolysis because of differences in catalytic efficiency. Consistent with this requirement, higher levels of glyceraldehyde-3-phosphate dehydrogenase were observed with two-dimensi...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.173.1.245-254.1991
更新日期:1991-01-01 00:00:00
abstract::The O antigen is an important cell wall antigen of gram-negative bacteria, and the genes responsible for its biosynthesis are located in a gene cluster. We have cloned and sequenced the DNA segment unique to the O-antigen gene cluster of Salmonella enterica group D3. This segment includes a novel O-antigen polymerase ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.180.4.1002-1007.1998
更新日期:1998-02-01 00:00:00
abstract::The nucleotide sequence of the DNA mobilization region of the 5-nitroimidazole resistance plasmid pIP421, from strain BF-F239 of Bacteroides fragilis, was determined. It contains a putative origin of transfer (oriT) including three sets of inverted repeats and two sequences reminiscent of specific integration host fac...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.179.12.4071-4074.1997
更新日期:1997-06-01 00:00:00
abstract::The Bacillus subtilis PurR mediates adenine repression and guanosine induction of purA. PRPP inhibits binding of PurR to DNA in vitro. Mutations in the PRPP binding motif of PurR caused strong repression regardless of purine exclusions or additions, establishing the role of PRPP as regulator of PurR. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.185.22.6728-6731.2003
更新日期:2003-11-01 00:00:00
abstract::The Escherichia coli HtrA protein is a periplasmic protease/chaperone that is upregulated under stress conditions. The protease and chaperone activities of HtrA eliminate or refold damaged and unfolded proteins in the bacterial periplasm that are generated upon stress conditions. In the absence of substrates, HtrA oli...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01187-08
更新日期:2009-03-01 00:00:00
abstract::Chlamydiae are widespread Gram-negative pathogens of humans and animals. Salicylidene acylhydrazides, developed as inhibitors of type III secretion system (T3SS) in Yersinia spp., have an inhibitory effect on chlamydial infection. However, these inhibitors also have the capacity to chelate iron, and it is possible tha...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01677-14
更新日期:2014-08-15 00:00:00
abstract::Intracellular serine proteases of Bacillus licheniformis and Bacillus subtilis are closely related. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.137.2.1017-1019.1979
更新日期:1979-02-01 00:00:00
abstract::The effect of sublethal, midlethal, and lethal doses of total-body X irradiation on the fecal microbial population of the rat was studied. No changes were observed in animals receiving sublethal doses of X ray. Midlethal and lethal doses produced an increase in the numbers of fecal coliforms, staphylococci, streptococ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.94.2.378-382.1967
更新日期:1967-08-01 00:00:00
abstract::The origin of replication of the plasmid R1162 contains an initiation site for the synthesis of each DNA strand. When one of these sites (oriL) is deleted, synthesis on the corresponding strand is no longer initiated efficiently in vitro by the R1162-encoded replication proteins, and the plasmid is no longer stably ma...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.178.16.4870-4876.1996
更新日期:1996-08-01 00:00:00
abstract::Rhodocyclales are representative of versatile bacteria that are able to utilize a wide variety of organic compounds for growth, but only a few strains have been isolated in pure culture thus far. Here we present the genome sequence of Methyloversatilis universalis FAM5(T), the first cultivable methylotrophic member of...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.05331-11
更新日期:2011-09-01 00:00:00
abstract::The flagellar regulon of Brucella melitensis 16M contains 31 genes clustered in three loci on the small chromosome. These genes encode a polar sheathed flagellum that is transiently expressed during vegetative growth and required for persistent infection in a mouse model. By following the expression of three flagellar...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00712-06
更新日期:2007-01-01 00:00:00
abstract::The cheF gene, which is involved in chemotaxis in Bacillus subtilis, has been cloned, expressed, and sequenced. This gene is contained in a 0.7-kilobase PstI DNA fragment that was isolated from a lambda Charon 4A B. subtilis chromosomal DNA library. This fragment was subcloned into the expression vector pSI-1 and show...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.171.3.1631-1637.1989
更新日期:1989-03-01 00:00:00
abstract::Several mutants of Bacillus subtilis deficient in catalase synthesis generated by nitrosoguanidine mutagenesis have been used to map a locus affecting catalase activity. Two- and three-factor bacteriophage PBS1 transductional crosses were used to locate the locus, named katA, between recH and thiA with 98% linkage to ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.169.12.5848-5851.1987
更新日期:1987-12-01 00:00:00
abstract::Synthesis of the autoinducer signal involved in the cell density-dependent activation of Vibrio fischeri luminescence is directed by luxI. The autoinducer is N-(3-oxohexanoyl)homoserine lactone, and little is known about its synthesis. We have measured autoinducer synthesis by amino acid auxotrophs of Escherichia coli...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.178.17.5291-5294.1996
更新日期:1996-09-01 00:00:00
abstract::Bacteriophage T7 RNA polymerase is stable in Escherichia coli but very susceptible to cleavage by at least one endoprotease after cell lysis. The major source of this endoprotease activity was found to be localized to the outer membrane of the cell. A rapid whole-cell assay was developed to screen different strains fo...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.170.3.1245-1253.1988
更新日期:1988-03-01 00:00:00
abstract::Eleven conditional lethal dnaG(Ts) mutations were located by chemical cleavage of heteroduplexes formed between polymerase chain reaction-amplified DNAs from wild-type and mutant dnaG genes. This entailed end labeling one DNA strand of the heteroduplex, chemically modifying the strands with hydroxylamine or osmium tet...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.173.3.1268-1278.1991
更新日期:1991-02-01 00:00:00