Abstract:
:Atomic force microscopy was used to measure the thickness of air-dried, collapsed murein sacculi from Escherichia coli K-12 and Pseudomonas aeruginosa PAO1. Air-dried sacculi from E. coli had a thickness of 3.0 nm, whereas those from P. aeruginosa were 1.5 nm thick. When rehydrated, the sacculi of both bacteria swelled to double their anhydrous thickness. Computer simulation of a section of a model single-layer peptidoglycan network in an aqueous solution with a Debye shielding length of 0.3 nm gave a mass distribution full width at half height of 2.4 nm, in essential agreement with these results. When E. coli sacculi were suspended over a narrow groove that had been etched into a silicon surface and the tip of the atomic force microscope used to depress and stretch the peptidoglycan, an elastic modulus of 2.5 x 10(7) N/m(2) was determined for hydrated sacculi; they were perfectly elastic, springing back to their original position when the tip was removed. Dried sacculi were more rigid with a modulus of 3 x 10(8) to 4 x 10(8) N/m(2) and at times could be broken by the atomic force microscope tip. Sacculi aligned over the groove with their long axis at right angles to the channel axis were more deformable than those with their long axis parallel to the groove axis, as would be expected if the peptidoglycan strands in the sacculus were oriented at right angles to the long cell axis of this gram-negative rod. Polar caps were not found to be more rigid structures but collapsed to the same thickness as the cylindrical portions of the sacculi. The elasticity of intact E. coli sacculi is such that, if the peptidoglycan strands are aligned in unison, the interstrand spacing should increase by 12% with every 1 atm increase in (turgor) pressure. Assuming an unstressed hydrated interstrand spacing of 1.3 nm (R. E. Burge, A. G. Fowler, and D. A. Reaveley, J. Mol. Biol. 117:927-953, 1977) and an internal turgor pressure of 3 to 5 atm (or 304 to 507 kPa) (A. L. Koch, Adv. Microbial Physiol. 24:301-366, 1983), the natural interstrand spacing in cells would be 1.6 to 2.0 nm. Clearly, if large macromolecules of a diameter greater than these spacings are secreted through this layer, the local ordering of the peptidoglycan must somehow be disrupted.
journal_name
J Bacterioljournal_title
Journal of bacteriologyauthors
Yao X,Jericho M,Pink D,Beveridge Tdoi
10.1128/JB.181.22.6865-6875.1999keywords:
subject
Has Abstractpub_date
1999-11-01 00:00:00pages
6865-75issue
22eissn
0021-9193issn
1098-5530journal_volume
181pub_type
杂志文章abstract::In this communication we present evidence that indicates that 1,2-propanediol (1,2-PDL) is a positive effector of the transcription of the cobalamin (vitamin B12) biosynthetic (cob) operon and of the 1,2-PDL utilization (pdu) genes. The stimulatory effects of 1,2-PDL were demonstrated using Mu d-lac transcriptional fu...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.174.7.2267-2272.1992
更新日期:1992-04-01 00:00:00
abstract::Globomycin is an antibiotic which inhibits the processing of the prolipoprotein. Eighty globomycin-resistant mutants were independently isolated from Escherichia coli K-12 which had a deletion mutation in chromosomal lipoprotein gene (lpp), but contained a plasmid carrying the wild-type lpp gene. Twenty-six of the mut...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.145.1.654-656.1981
更新日期:1981-01-01 00:00:00
abstract::Exogenously supplied long-chain fatty acids have been shown to markedly alleviate the inhibition of phototrophic growth of cultures of Rhodopseudomonas sphaeroides caused by the antibiotic cerulenin. Monounsaturated and polyunsaturated C18 fatty acids were most effective in relieving growth inhibition mediated by ceru...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.153.2.782-790.1983
更新日期:1983-02-01 00:00:00
abstract::Evidence of the presence of messenger ribonucleic acid (mRNA) in dormant spores of Bacillus subtilis has been obtained. The bulk RNA from spores was isolated and labeled in vitro with tritiated dimethyl sulfate. The spore RNA hybridized to 2.4 to 3.2% of the B. subtilis genome. The RNA hybridized to both the complemen...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.119.2.514-521.1974
更新日期:1974-08-01 00:00:00
abstract::Holwerda, Jack (Michigan Department of Health, Grand Rapids) and Grace Eldering. Culture and fluorescent-antibody methods in diagnosis of whooping cough. J. Bacteriol. 86:449-451. 1963.-Nasopharyngeal swabs from 517 suspected whooping-cough patients were examined by culture and by fluorescent-antibody (FA) staining pr...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.86.3.449-451.1963
更新日期:1963-09-01 00:00:00
abstract::Band 7 proteins, which encompass members of the stomatin, prohibitin, flotillin, and HflK/C protein families, are integral membrane proteins that play important physiological roles in eukaryotes but are poorly characterized in bacteria. We have studied the band 7 proteins encoded by the cyanobacterium Synechocystis sp...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00644-09
更新日期:2009-10-01 00:00:00
abstract::A mutant affected in the b subunit (coded by the uncF gene) of the F1F0-ATPase in Escherichia coli was isolated by a localized mutagenesis procedure in which a plasmid carrying the unc genes was mutagenized in vivo. The biochemical properties of cells carrying the uncF515 allele were examined in a strain carrying the ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.162.1.420-426.1985
更新日期:1985-04-01 00:00:00
abstract::The TOL plasmid originally isolated in Pseudomonas putida (arvilla) mt-2 was transmissible to strains of the fluorescens group of Pseudomonas, i.e., P. putida, P. fluorescens, and P. aeruginosa, except for a strain of P. aeruginosa, strain PAO. The same strain, however, could accept the plasmid when its restriction an...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.133.2.527-535.1978
更新日期:1978-02-01 00:00:00
abstract::Two low-molecular-weight basic proteins, termed A and B proteins, comprise about 15% of the protein of dormant spores of Bacillus megaterium. Irradiation of intact dormant spores with ultraviolet light results in covalent cross-linking of the A and B proteins to other spore macromolecules. The cross-linked A and B pro...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.139.2.486-494.1979
更新日期:1979-08-01 00:00:00
abstract::The essential function of penicillin-binding protein 2 (PBP2) in methicillin-susceptible Staphylococcus aureus RN4220 was clearly established by placing the pbp2 gene under control of the inducible P(spac) promoter; the resulting bacteria were unable to grow in the absence of inducer. In contrast, the deficit in PBP2 ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.183.22.6525-6531.2001
更新日期:2001-11-01 00:00:00
abstract::The Rhizobium phaseoli recA gene has been cloned by interspecific complementation of the Fec phenotype of bacteriophage lambda. The cloned gene restored the recombination proficiency and conferred resistance to DNA-damaging agents (methyl methanesulfonate and nitrofurantoin) to an Escherichia coli recA mutant. The dir...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.173.10.3035-3040.1991
更新日期:1991-05-01 00:00:00
abstract::Hydrolytic deamination of cytosine to uracil in DNA is increased in organisms adapted to high temperatures. Hitherto, the uracil base excision repair (BER) pathway has only been described in two archaeons, the crenarchaeon Pyrobaculum aerophilum and the euryarchaeon Archaeoglobus fulgidus, which are hyperthermophiles ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00233-11
更新日期:2011-09-01 00:00:00
abstract::Pyridine nucleotide-dependent glucose dehydrogenase activity (GPND) is described for the first time in cell-free extracts of certain blue-green algae. When glucose is added to these crude cell extracts, nicotinamide adenine dinucleotide phosphate is reduced at twice the rate as nicotinamide adenine dinucleotide; but e...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.114.1.28-33.1973
更新日期:1973-04-01 00:00:00
abstract::Cells of Pseudomonas aeruginosa resistant to benzalkonium chloride (BC) underwent unique ultrastructural reorganizations when they were grown in the presence of 1 mg of BC/ml. The resistant cells usually contained a single, centrally positioned pseudovacuole. The pseudovacuole was surrounded by a diffuse substance tha...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.113.1.409-416.1973
更新日期:1973-01-01 00:00:00
abstract::Escherichia coli K-12 strains contain a cytoplasmic activity, peptidase N, capable of hydrolyzing alanine-p-nitroanilide. Mutations in the structural gene for the enzyme, pepN, were mapped, and the properties of mutant strains were examined. The pepN locus lay between ompF and asnS at approximately 20.8 min on the E. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:
更新日期:1982-11-01 00:00:00
abstract::Inhibition of sterol uptake in Saccharomyces cerevisiae sterol auxotroph FY3 (alpha hem1 erg7 ura) by delta-aminolevulinic acid (ALA) is dependent on the ability of the organism to synthesize heme from ALA. Sterol-depleted cells not exposed to ALA or strain PFY3 cells, with a double heme mutation, exposed to ALA did n...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.169.8.3707-3711.1987
更新日期:1987-08-01 00:00:00
abstract::The alpha-aminoadipate pathway for the biosynthesis of lysine is present only in fungi and euglena. Until now, this unique metabolic pathway has never been investigated in the opportunistic fungal pathogens Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus. Five of the eight enzymes (homocitrate syn...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.174.22.7379-7384.1992
更新日期:1992-11-01 00:00:00
abstract::Desulfurococcus kamchatkensis is an anaerobic organotrophic hyperthermophilic crenarchaeon isolated from a terrestrial hot spring. Its genome consists of a single circular chromosome of 1,365,223 bp with no extrachromosomal elements. A total of 1,474 protein-encoding genes were annotated, among which 205 are exclusive...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01525-08
更新日期:2009-04-01 00:00:00
abstract::Sites of transposon Tn7 insertion in the Escherichia coli chromosome were examined, and two distinct classes of target sites differing in nucleotide sequence were identified. The target site choice was found to be determined by Tn7-encoded transposition genes. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.172.5.2774-2778.1990
更新日期:1990-05-01 00:00:00
abstract::Bacteriocin 41 (Bac41) is produced from clinical isolates of Enterococcus faecalis and consists of two extracellular proteins, BacL1 and BacA. We previously reported that BacL1 protein (595 amino acids, 64.5 kDa) is a bacteriolytic peptidoglycan D-isoglutamyl-L-lysine endopeptidase that induces cell lysis of E. faecal...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.02203-14
更新日期:2015-01-01 00:00:00
abstract::The Bacillus anthracis endospore loses resistance properties during germination when its cortex peptidoglycan is degraded by germination-specific lytic enzymes (GSLEs). Although this event normally employs several GSLEs for complete cortex removal, the SleB protein alone can facilitate enough cortex hydrolysis to prod...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00869-10
更新日期:2011-01-01 00:00:00
abstract::Porphyromonas gingivalis, an obligate anaerobe, exhibits a relatively high degree of aerotolerance and possesses superoxide dismutase (SOD) which is induced by exposure to air. To clarify roles for SOD in this organism, the gene encoding SOD (sod) on the P. gingivalis chromosome was disrupted in a gene-directed way by...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.176.7.1939-1943.1994
更新日期:1994-04-01 00:00:00
abstract::Quantitative mass conversion of intact bacterial cells of Bacillus subtilis and B. licheniformis to L-phase variants has been effected after lysozyme treatment. After subculture of the unstable L-phase variants for several months in the presence of methicillin, stable L-phase variants were obtained which grew in the a...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.116.1.456-465.1973
更新日期:1973-10-01 00:00:00
abstract::A psychrotolerant marine bacterial strain, designated JUB59(T), was isolated from Antarctic surface seawater and classified as a new species of the genus Bizionia. Here, we present the first draft genome sequence for this genus, which suggests interesting features such as UV resistance, hydrolytic exoenzymes, and nitr...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.06245-11
更新日期:2011-12-01 00:00:00
abstract::We have mapped a regulatory site mediating the hyperproduction of cholera toxin in mutants of Vibrio cholerae strain 569B. Mutations in this locus, called htx, result in the hypertoxinogenic phenotype, as measured by the ganglioside filter assay and immunoradial diffusion. Transposon-facilitated recombination was used...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.139.3.859-865.1979
更新日期:1979-09-01 00:00:00
abstract::We show that hisT function is required for normal growth of Escherichia coli K-12, since a lack of hisT-mediated pseudouridine tRNA modification causes a uracil requirement that interferes with cell division. We also show that hisT transcription is positively growth rate regulated in exponentially growing bacteria and...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.173.22.7395-7400.1991
更新日期:1991-11-01 00:00:00
abstract::Expression of the major porin structural genes, ompF and ompC, is influenced by medium osmotic strength and requires the products of two regulatory genes, ompR and envZ. To help define the sites required for the expression of both porin genes, we have used a novel selection to identify mutations that decrease ompF tra...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.162.3.1054-1060.1985
更新日期:1985-06-01 00:00:00
abstract::Tn2424, a multiresistance transposon 25 kilobases long, was isolated from IncFII plasmid NR79. Tn2424 transposed resistance to sulfonamides, streptomycin and spectinomycin, mercuric chloride, chloramphenicol, and amikacin with a frequency of 6 X 10(-5). Resistance to amikacin was mediated by a 6'-N-acetyltransferase, ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.155.2.755-760.1983
更新日期:1983-08-01 00:00:00
abstract::The obligate intracellular pathogen Chlamydia trachomatis expresses a type III secretion system (T3SS) which has the potential to contribute significantly to pathogenesis. Based on a demonstrated role of type III secretion (T3S)-specific chaperones in the secretion of antihost proteins by gram-negative pathogens, we i...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.187.18.6466-6478.2005
更新日期:2005-09-01 00:00:00
abstract::During development of the symbiotic soil bacterium Sinorhizobium meliloti into nitrogen-fixing bacteroids, DNA replication and cell division cease and the cells undergo profound metabolic and morphological changes. Regulatory genes controlling the early stages of this process have not been identified. As a first step ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.183.10.3204-3210.2001
更新日期:2001-05-01 00:00:00