Abstract:
:Most small multicopy antibiotic-resistance plasmids of Staphylococcus aureus contain a major axis of hyphenated dyad symmetry (palA) that is required for normal replication and stability, although located outside of the minimal replicon. Rearrangements affecting palA cause plasmid instability, a marked reduction in copy number, and the accumulation of large quantities of strand-specific circular single-stranded plasmid DNA. In view of the recent observation that pT181 initiates replication by a nick and 3'-extension mechanism (S. Khan, personal communication), it is suggested that these plasmids replicate by an asymmetric rolling-circle mechanism in which the displaced plus strand remains single stranded until palA is exposed, forming a hairpin that serves as the lagging strand origin.
journal_name
Proc Natl Acad Sci U S Aauthors
Gruss AD,Ross HF,Novick RPdoi
10.1073/pnas.84.8.2165subject
Has Abstractpub_date
1987-04-01 00:00:00pages
2165-9issue
8eissn
0027-8424issn
1091-6490journal_volume
84pub_type
杂志文章abstract::Immobilization antigens of stock 51 of Paramecium tetraurelia were subjected to electrophoresis in NaDodSO(4)/polyacrylamide gels. Type A is estimated to have a molecular size of 300,000 daltons; H is estimated to be 288,000, D to be 280,000, E to be 270,000, B to be 253,000, and C to be 250,000. Poly(A)(+)RNAs have b...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.78.11.6776
更新日期:1981-11-01 00:00:00
abstract::The effect of phagocytosis on lectin binding to plasma membranes of polymorphonuclear leukocytes was examined. The specific activities of binding sites of concanavalin A and Ricinus communis agglutinin (defined as mug of lectin bound per 100 mug of membrane protein) were measured on isolated membranes; they decreased ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.71.2.394
更新日期:1974-02-01 00:00:00
abstract::An ammonia-oxidizing, carbon-fixing archaeon, Candidatus "Nitrosopumilus maritimus," recently was isolated from a salt-water aquarium, definitively confirming that chemoautotrophy exists among the marine archaea. However, in other incubation studies, pelagic archaea also were capable of using organic carbon. It has re...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0510157103
更新日期:2006-04-25 00:00:00
abstract::Direct conversion of carbon dioxide to multicarbon products remains as a grand challenge in electrochemical CO2 reduction. Various forms of oxidized copper have been demonstrated as electrocatalysts that still require large overpotentials. Here, we show that an ensemble of Cu nanoparticles (NPs) enables selective form...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1711493114
更新日期:2017-10-03 00:00:00
abstract::A cell line has been developed from the imaginal wing discs of the lepidopteran insect Trichoplusia ni (Hübner). The cells grow in suspension as fluid-filled, multicellular vesicles. The cell line has been designated IAL-TND1. Two-dimensional electrophoresis (isoelectric focusing and sodium dodecyl sulfate/polyacrylam...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.79.8.2589
更新日期:1982-04-01 00:00:00
abstract::FIP-3 (14.7K interacting protein) was discovered during a search for cell proteins that could interact with an adenovirus protein (Ad E3-14.7K) that had been shown to prevent tumor necrosis factor (TNF)-alpha-induced cytolysis. FIP-3, which contains leucine zippers and a zinc finger domain, inhibits both basal and ind...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.96.3.1042
更新日期:1999-02-02 00:00:00
abstract::Oscillatory activity is widespread in dynamic neuronal networks. The main paradigm for the origin of periodicity consists of specialized pacemaking elements that synchronize and drive the rest of the network; however, other models exist. Here, we studied the spontaneous emergence of synchronized periodic bursting in a...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1515105113
更新日期:2016-03-22 00:00:00
abstract::Two RNA fractions have been isolated and purified from both oncogenic and nononcogenic strains of Agrobacterium tumefaciens. Both RNAs are capable of inducing the formation of transplantable tumors when introduced at wound sites in stems of Datura stramonium plants. One of these RNA fractions was found to be bound to ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.71.5.1585
更新日期:1974-05-01 00:00:00
abstract::Atherosclerosis is associated with alterations in nitric oxide (NO)/cGMP signaling. In early stages of the disease, inflammatory and possibly other cells produce reactive oxygen species that scavenge vasoprotective NO. In addition to the oxidative stress, expression and activity of enzymes downstream to NO formation m...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0405509101
更新日期:2004-11-23 00:00:00
abstract::Chloroplast DNA of the protozoan flagellate, Euglena gracilis, exists as circular molecules, 40 mum in contour length, as shown by electron microscopy and buoyant density analyses. ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.68.6.1169
更新日期:1971-06-01 00:00:00
abstract::Binding and uptake of alpha-fetoprotein (AFP) by mouse T-lymphoma YAC-1 cells exhibited the characteristics of receptor-mediated endocytosis. The binding saturation curve obtained by incubating YAC-1 cells at 4 degrees C with 125I-labeled AFP at different concentrations (50 ng/ml to 2.5 mg/ml) showed three saturation ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.82.10.3301
更新日期:1985-05-01 00:00:00
abstract::Unrestrained 53BP1 activity at DNA double-strand breaks (DSBs) hampers DNA end resection and upsets DSB repair pathway choice. RNF169 acts as a molecular rheostat to limit 53BP1 deposition at DSBs, but how this fine balance translates to DSB repair control remains undefined. In striking contrast to 53BP1, ChIP analyse...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1804823115
更新日期:2018-08-28 00:00:00
abstract::We investigated the ultrafast structural transitions of the heme induced by nitric oxide (NO) binding for several heme proteins by subpicosecond time-resolved resonance Raman and femtosecond transient absorption spectroscopy. We probed the heme iron motion by the evolution of the iron-histidine Raman band intensity af...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0912938107
更新日期:2010-08-03 00:00:00
abstract::We recently found that scatter factor (SF), a cell motility factor with a multimodular structure, is identical to hepatocyte growth factor (HGF), a potent mitogen of various cell types. SF/HGF is the ligand of the c-Met receptor tyrosine kinase. Here we used transient expression of naturally occurring and in vitro mut...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.89.23.11574
更新日期:1992-12-01 00:00:00
abstract::For almost a century, alcohols have been thought to produce their effects by actions on the membrane lipids of central nervous system neurons--the well known "lipid theory" of alcohol action. The rationale for this theory is the correlation of potency with oil/water or membrane/buffer partition coefficient. Although a...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.91.17.8200
更新日期:1994-08-16 00:00:00
abstract::We have obtained long-term cultures of differentiated proliferating follicular cells from normal adult human thyroid glands. In vitro growth of such human cells has been sustained by a modified F-12 medium, supplemented with bovine hypothalamus and pituitary extracts and no added thyrotropin. Cultures have been expand...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.91.19.9004
更新日期:1994-09-13 00:00:00
abstract::Functional reconstitution of membrane proteins within lipid bilayers is crucial for understanding their biological function in living cells. While this strategy has been extensively used with liposomes, reconstitution of membrane proteins in lipidic cubic mesophases presents significant challenges related to the struc...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1603965113
更新日期:2016-07-05 00:00:00
abstract::Over the past years, family 18 chitinases have been validated as potential targets for the design of drugs against human pathogens that contain or interact with chitin during their normal life cycles. Thus far, only one potent chitinase inhibitor has been described in detail, the pseudotrisaccharide allosamidin. Recen...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.132060599
更新日期:2002-07-09 00:00:00
abstract::The rhizobium-legume symbiosis has been widely studied as the model of mutualistic evolution and the essential component of sustainable agriculture. Extensive genetic and recent genomic studies have led to the hypothesis that many distinct strategies, regardless of rhizobial phylogeny, contributed to the varied rhizob...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1120436109
更新日期:2012-05-29 00:00:00
abstract::Transcription antitermination by lambda N gene product is affected in a mutant Escherichia coli with altered ribosomal protein S10, caused by the nusE71 mutation. To study the role of translation in antitermination, we have fused the phage nutR locus, the site of action of N, with the lac regulatory region. We have mo...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.81.12.3612
更新日期:1984-06-01 00:00:00
abstract::Within the mammalian testis, specialized tight junctions between somatic Sertoli cells create basal and apical polarity within the cells, restrict movement of molecules between cells, and separate the seminiferous epithelium into basal and adluminal compartments. These tight junctions form the basis of the blood-testi...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0506084102
更新日期:2005-11-15 00:00:00
abstract::Chylomicron catabolism is known to be initiated by the enzyme lipoprotein lipase (triacylglycero-protein acylhydrolase, EC 3.1.1.34). Chylomicron remnants, produced by lipolysis, are rapidly taken up by the liver via an apolipoprotein E (apoE)-mediated, receptor-dependent process. The low density lipoprotein (LDL) rec...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.88.19.8342
更新日期:1991-10-01 00:00:00
abstract::Restricted fetal growth is associated with postnatal mortality and morbidity and may be directly related to alterations in the capacity of the placenta to supply nutrients. We proposed previously that imprinted genes can regulate nutrient supply by the placenta. Here, we tested the hypothesis that the insulin-like gro...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0402508101
更新日期:2004-05-25 00:00:00
abstract::The serine proteases sequentially activated to form a fibrin clot are inhibited primarily by members of the serpin family, which use a unique beta-sheet expansion mechanism to trap and destroy their targets. Since the discovery that serpins were a family of serine protease inhibitors there has been controversy as to t...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.162232399
更新日期:2002-08-20 00:00:00
abstract::Cytoplasmic dynein is a microtubule-based motor protein complex that plays important roles in a wide range of fundamental cellular processes, including vesicular transport, mitosis, and cell migration. A single major form of cytoplasmic dynein associates with membranous organelles, mitotic kinetochores, the mitotic an...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0703614104
更新日期:2007-06-12 00:00:00
abstract::Scattering of light from dielectric particles whose size is on the order of an optical wavelength underlies a plethora of visual phenomena in nature and is a foundation for optical coatings and paints. Tailoring the internal nanoscale geometry of such "photonic particles" allows tuning their optical scattering charact...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1601777113
更新日期:2016-06-21 00:00:00
abstract::Investigations into the biophysical properties of single molecules traditionally involve well defined in vitro systems where parameters such as solvent viscosity and applied forces are known a priori. These systems provide means to develop models describing the polymers response to a variety of conditions, including t...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0812723106
更新日期:2009-06-09 00:00:00
abstract::Biochemically, the syntrophic bacteria constitute the missing link in our understanding of anaerobic flow of carbon in the biosphere. The completed genome sequence of Syntrophus aciditrophicus SB, a model fatty acid- and aromatic acid-degrading syntrophic bacterium, provides a glimpse of the composition and architectu...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0610456104
更新日期:2007-05-01 00:00:00
abstract::It is well known that two regular tetrahedra can be combined with a single regular octahedron to tile (complete fill) three-dimensional Euclidean space . This structure was called the "octet truss" by Buckminster Fuller. It was believed that such a tiling, which is the Delaunay tessellation of the face-centered cubic ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1105594108
更新日期:2011-07-05 00:00:00
abstract::Promoter-proximal stalling, a general phenomenon observed during the expression of many RNA polymerase II transcribed genes, is dependent on transcription factor IIH (TFIIH). Reactions lacking TFIIH initiated transcription, but the transcription complex encountered a block to elongation proximal to the promoter. The a...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.95.17.9767
更新日期:1998-08-18 00:00:00