Abstract:
:Guanosine tetraphosphate (ppGpp) is a key mediator of stringent control, an adaptive response of bacteria to amino acid starvation, and has thus been termed a bacterial alarmone. Previous X-ray crystallographic analysis has provided a structural basis for the transcriptional regulation of RNA polymerase activity by ppGpp in the thermophilic bacterium Thermus thermophilus. Here we investigated the physiological basis of the stringent response by comparing the changes in intracellular ppGpp levels and the rate of RNA synthesis in stringent (rel(+); wild type) and relaxed (relA and relC; mutant) strains of T. thermophilus. We found that in wild-type T. thermophilus, as in other bacteria, serine hydroxamate, an amino acid analogue that inhibits tRNA(Ser) aminoacylation, elicited a stringent response characterized in part by intracellular accumulation of ppGpp and that this response was completely blocked in a relA-null mutant and partially blocked in a relC mutant harboring a mutation in the ribosomal protein L11. Subsequent in vitro assays using ribosomes isolated from wild-type and relA and relC mutant strains confirmed that (p)ppGpp is synthesized by ribosomes and that mutation of RelA or L11 blocks that activity. This conclusion was further confirmed in vitro by demonstrating that thiostrepton or tetracycline inhibits (p)ppGpp synthesis. In an in vitro system, (p)ppGpp acted by inhibiting RNA polymerase-catalyzed 23S/5S rRNA gene transcription but at a concentration much higher than that of the observed intracellular ppGpp pool size. On the other hand, changes in the rRNA gene promoter activity tightly correlated with changes in the GTP but not ATP concentration. Also, (p)ppGpp exerted a potent inhibitory effect on IMP dehydrogenase activity. The present data thus complement the earlier structural analysis by providing physiological evidence that T. thermophilus does produce ppGpp in response to amino acid starvation in a ribosome-dependent (i.e., RelA-dependent) manner. However, it appears that in T. thermophilus, rRNA promoter activity is controlled directly by the GTP pool size, which is modulated by ppGpp via inhibition of IMP dehydrogenase activity. Thus, unlike the case of Escherichia coli, ppGpp may not inhibit T. thermophilus RNA polymerase activity directly in vivo, as recently proposed for Bacillus subtilis rRNA transcription (L. Krasny and R. L. Gourse, EMBO J. 23:4473-4483, 2004).
journal_name
J Bacterioljournal_title
Journal of bacteriologyauthors
Kasai K,Nishizawa T,Takahashi K,Hosaka T,Aoki H,Ochi Kdoi
10.1128/JB.00574-06subject
Has Abstractpub_date
2006-10-01 00:00:00pages
7111-22issue
20eissn
0021-9193issn
1098-5530pii
188/20/7111journal_volume
188pub_type
杂志文章abstract::The S-layers of Thermus thermophilus HB27 and T. thermophilus HB8 are composed of protein units of 95 kDa (P95) and 100 kDa (P100), respectively. We have selected S-layer deletion mutants from both strains by complete replacement of the slpA gene. Mutants of the two strains showed similar defects in growth and morphol...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.177.19.5460-5466.1995
更新日期:1995-10-01 00:00:00
abstract::The bacterial peptidoglycan consists of glycan chains of repeating beta-1,4-linked N-acetylglucosaminyl-N-acetylmuramyl units cross-linked through short peptide chains. The polymerization of the glycans, or glycosyltransfer (GT), and transpeptidation (TP) are catalyzed by bifunctional penicillin-binding proteins (PBPs...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.185.15.4418-4423.2003
更新日期:2003-08-01 00:00:00
abstract::The fumarate reductase enzyme complex allows Escherichia coli to grow anaerobically with fumarate as a terminal electron acceptor for oxidative phosphorylation when the preferred compounds oxygen and nitrate are not available. We used the pKO promoter test vectors to identify a single promoter for the frdABCD genes wh...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.164.3.1100-1109.1985
更新日期:1985-12-01 00:00:00
abstract::In Streptococcus mutans, enzyme II(scr) and sucrose-6-phosphate hydrolase are two important enzymes in the transport and metabolism of dietary sucrose. The scr regulon of S. mutans is composed of three genes, scrA and scrB, which code for enzyme II(scr) and sucrose-6-phosphate hydrolase, respectively, and scrR, which ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.185.19.5791-5799.2003
更新日期:2003-10-01 00:00:00
abstract::This is the first study of sporogenesis in Streptomyces carried out on a relatively high number of species (seven) which allows us, using also previously published results, to establish a general picture of this process. In the sporogenesis of Streptomyces two basic stages can be considered: the sporulation septum syn...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.127.3.1443-1454.1976
更新日期:1976-09-01 00:00:00
abstract::Streptococcus pyogenes (group A streptococcus [GAS]), a catalase-negative gram-positive bacterium, is aerotolerant and survives H2O2 exposures that kill many catalase-positive bacteria. The molecular basis of the H2O2 resistance is poorly known. Here, we demonstrate that serotype M49 GAS lacking the Rgg regulator is m...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01843-07
更新日期:2008-05-01 00:00:00
abstract::Aeromonas hydrophila secretes a number of degradative enzymes and toxins into the external milieu via the type II secretory pathway or secreton. ExeA is an essential component of this system and is necessary for the localization and/or multimerization of the secretin ExeD. ExeA contains two sequence motifs characteris...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.187.18.6370-6378.2005
更新日期:2005-09-01 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::Day, L. E. (Chas. Pfizer & Co., Inc., Groton, Conn.). Tetracycline inhibition of cell-free protein synthesis. II. Effect of the binding of tetracycline to the components of the system. J. Bacteriol. 92:197-203. 1966.-When tetracycline, an inhibitor of cell-free protein synthesis, was preincubated with each component o...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.92.1.197-203.1966
更新日期:1966-07-01 00:00:00
abstract::Glyoxal is toxic and mutagenic α-oxoaldehyde generated in vivo as an oxidation by-product of sugar metabolism. We selected glyoxal-resistant mutants from an Escherichia coli strain lacking major glyoxal-detoxifying genes, gloA and yqhD, by growing cells in medium containing a lethal concentration of glyoxal. The mutan...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.06062-11
更新日期:2012-04-01 00:00:00
abstract::Legionella pneumophila expresses two peroxide-scavenging alkyl hydroperoxide reductase systems (AhpC1 and AhpC2D) that are expressed differentially during the bacterial growth cycle. Functional loss of the postexponentially expressed AhpC1 system is compensated for by increased expression of the exponentially expresse...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00141-08
更新日期:2008-05-01 00:00:00
abstract::Our previous work showed that pap pilin gene transcription is subject to a thermoregulatory control mechanism under which pap pilin is not transcribed at a low temperature (23 degrees C) (L. B. Blyn, B. A. Braaten, C. A. White-Ziegler, D. H. Rolfson, and D. A. Low, EMBO J. 8:613-620, 1989). In order to isolate genes i...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.174.21.7003-7012.1992
更新日期:1992-11-01 00:00:00
abstract::Bacteroides thetaiotaomicron, a gram-negative obligate anaerobe, appears to utilize starch by first binding the polymer to its surface and then translocating it into the periplasmic space. Several genes that encode enzymes or outer membrane proteins involved in starch utilization have been identified. These have been ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.178.24.7180-7186.1996
更新日期:1996-12-01 00:00:00
abstract::The cysteine-rich envelope proteins of the elementary body form of chlamydiae are thought to be located in the outer membrane on the basis of their insolubility in the weak anionic detergent N-lauryl sarcosinate (Sarkosyl). We found, however, that the insolubility of the small (EnvA) and the large (EnvB) cysteine-rich...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.177.4.877-882.1995
更新日期:1995-02-01 00:00:00
abstract::An unusual xylose isomerase produced by Thermoanaerobacterium strain JW/SL-YS 489 was purified 28-fold to gel electrophoretic homogeneity, and the biochemical properties were determined. Its pH optimum distinguishes this enzyme from all other previously described xylose isomerases. The purified enzyme had maximal acti...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.178.20.5938-5945.1996
更新日期:1996-10-01 00:00:00
abstract::Many DNA viruses concatemerize their genomes as a prerequisite to packaging into capsids. Concatemerization arises from either replication or homologous recombination. Replication is already the target of many antiviral drugs, and viral recombinases are an attractive target for drug design, particularly for combinatio...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.185.8.2465-2474.2003
更新日期:2003-04-01 00:00:00
abstract::Specific localization of the lysis (L) protein of bacteriophage MS2 in the cell wall of Escherichia coli was determined by immunoelectron microscopy. After induction of the cloned lysis gene, the cells were plasmolyzed, fixed, and embedded in either Epon or Lowicryl K4M. Polyclonal L-protein-specific antiserum was pur...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.171.6.3331-3336.1989
更新日期:1989-06-01 00:00:00
abstract::The trehalose content in Saccharomyces cerevisiae can be significantly manipulated by including trehalose at an appropriate level in the growth medium. Its uptake is largely dependent on the expression of AGT1, which encodes an alpha-glucoside transporter. The trehalose found in a tps1 mutant of trehalose synthase may...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.181.12.3830-3832.1999
更新日期:1999-06-01 00:00:00
abstract::Heme A, as a prosthetic group, is found exclusively in respiratory oxidases of mitochondria and aerobic bacteria. Bacillus subtilis CtaA and other heme A synthases catalyze the conversion of a methyl side group on heme O into a formyl group. The catalytic mechanism of heme A synthase is not understood, and little is k...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.187.24.8361-8369.2005
更新日期:2005-12-01 00:00:00
abstract::Tyrosine-mediated repression of aroF and tyrP was studied by inserting DNA sequences between the two adjacent TYR R boxes which, in each case, overlap the respective RNA polymerase binding sites of these genes. In both cases, repression was greatest when homologous regions of these two TYR R boxes were on the same fac...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.173.16.5079-5085.1991
更新日期:1991-08-01 00:00:00
abstract::Strains of Bacillus thuringiensis such as B. thuringiensis subsp. israelensis (ONR-60A) and B. thuringiensis subsp. morrisoni (PG-14) pathogenic for mosquito larvae produce a complex parasporal body consisting of several protein endotoxins synthesized during sporulation that form an aggregate of crystalline inclusions...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.06095-11
更新日期:2012-03-01 00:00:00
abstract::Accumulation of abnormal proteins in cells of bacteria or eukaryotes can induce synthesis of a set of heat shock proteins. We examined such induction following addition of azetidine (a proline analog) or synthesis of a heterologous protein (human prourokinase) in Escherichia coli. Synthesis of heat shock proteins unde...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.176.18.5648-5653.1994
更新日期:1994-09-01 00:00:00
abstract::A genomic library containing HindIII partial digests of Rhodopseudomonas sphaeroides HR DNA was constructed in the broad-host-range cosmid cloning vector pVK102. With a portion of this library as donor in complementation studies with the ribulose 1,5-bisphosphate carboxylase-oxygenase regulatory mutant R. sphaeroides ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.164.1.147-154.1985
更新日期:1985-10-01 00:00:00
abstract::Razin, S. (University of Connecticut, Storrs), M. E. Tourtellotte, R. N. McElhaney, and J. D. Pollack. Influence of lipid components of Mycoplasma laidlawii membranes on osmotic fragility of cells. J. Bacteriol. 91:609-616. 1966.-Lipid composition of Mycoplasma laidlawii membranes could be significantly changed by var...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.91.2.609-616.1966
更新日期:1966-02-01 00:00:00
abstract::Mutants defective in uptake or utilization of a given metabolite can readily be obtained from facultative auxotrophs (for that metabolite) by penicillin enrichment under nonpermissive conditions in the presence of a low level of the required metabolite. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.121.3.1216-1218.1975
更新日期:1975-03-01 00:00:00
abstract::A gene for the constitutive ribosephosphate isomerase (rpiA) is highly cotransducible with serA at 56.2 min on the genetic linkage map of Escherichia coli K-12. Suppression of ribosephosphate isomerase A-negative mutants can occur by a regulator gene mutation permitting constitutive synthesis of the normally inducible...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.118.3.1183-1185.1974
更新日期:1974-06-01 00:00:00
abstract::Escherichia coli K-12 strain CU1008 cannot use L-serine as the sole carbon source, but it could use L-serine as an auxiliary carbon source with glucose, L-alanine, or pyruvate and could derive energy from L-serine to support oxygen uptake. CU1008 grew with L-serine if it was also provided with glycine and leucine. The...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.151.2.777-782.1982
更新日期:1982-08-01 00:00:00
abstract::The number and disposition of flagella harbored by eubacteria are regulated by a specific trait successfully maintained over generations. The genes governing the number of flagella in Bacillus subtilis have never been identified, although the ifm locus has long been recognized to influence the motility phenotype of th...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.187.15.5356-5366.2005
更新日期:2005-08-01 00:00:00
abstract::ATP sulfurylase is a key enzyme in the energy-generating sulfur oxidation pathways of many chemoautotrophic bacteria. The utilization of reduced sulfur compounds to fuel CO2 fixation by the still-uncultured bacterial endosymbionts provides the basis of nutrition in invertebrates, such as the tubeworm Riftia pachyptila...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.176.12.3723-3729.1994
更新日期:1994-06-01 00:00:00
abstract::Fundamental questions in bacterial gene regulation concern how multiple regulatory proteins interact with the transcription apparatus at a single promoter and what are the roles of protein contacts with RNA polymerase and changes in DNA conformation. Transcription of the Escherichia coli uhpT gene, encoding the induci...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.181.23.7266-7273.1999
更新日期:1999-12-01 00:00:00