Abstract:
:The beta plasmid from Streptococcus faecalis strain DS5, which codes for resistance to erythromycin and lincomycin, was introduced into a Lancefield group F streptococcus, strain DR1501, by transformation. This strain, DR1501 (beta), was found to be an excellent donor of the beta plasmid and readily transferred the resistance markers to various lactic acid bacteria, including certain strains of S. mutans, S. sanguis, and S. salivarius. Evidence is presented indicating that the transfer of the beta plasmid is mediated by a mechanism that requires cell-to-cell contact. The transfer of plasmid DNA during conjugation has been confirmed by the isolation of beta plasmid from transconjugant clones and by their ability to then serve as donors of the erythromycin and lincomycin resistance markers.
journal_name
Proc Natl Acad Sci U S Aauthors
LeBlanc DJ,Hawley RJ,Lee LN,St Martin EJdoi
10.1073/pnas.75.7.3484subject
Has Abstractpub_date
1978-07-01 00:00:00pages
3484-7issue
7eissn
0027-8424issn
1091-6490journal_volume
75pub_type
杂志文章abstract::The steroidogenic acute regulatory protein (StAR) increases the movement of cholesterol from the outer to the inner membrane of adrenal and gonadal mitochondria, thus providing the substrate for steroid hormone biosynthesis. Deletion of 62 amino-terminal aa produces a cytoplasmic form of StAR (N-62 StAR) that lacks th...
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.96.13.7250
更新日期:1999-06-22 00:00:00
abstract::To determine whether bacterial ribosomes recognize a distinguishing feature in the immediate vicinity of actual initiator codons or are directed to these sites through involvement of other portion(s) of the mRNA molecule, the interaction between ribosomes and defined (32)P-labeled initiator fragments from R17 RNA was ...
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.70.9.2605
更新日期:1973-09-01 00:00:00
abstract::The peroxidase-catalyzed aerobic oxidation of a linear aldehyde, leading to the next lower homologue in the triplet state, is accompanied by Norrish type II product ethylene when the substrate is pentanal. This system appears to provide an example of "photobiochemistry without light" because ethylene is a plant hormon...
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.91.1.410
更新日期:1994-01-04 00:00:00
abstract::GTP hydrolysis by elongation factor Tu (EF-Tu), a translational GTPase that delivers aminoacyl-tRNAs to the ribosome, plays a crucial role in decoding and translational fidelity. The basic reaction mechanism and the way the ribosome contributes to catalysis are a matter of debate. Here we use mutational analysis in co...
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.1412676111
更新日期:2014-10-07 00:00:00
abstract::Spleen cells derived from a rabbit hyperimmunized with a Type III pneumococcal vaccine were exposed to simian virus 40 in vitro. After 114 days, transformed cells growing on the surface of one culture dish were observed and a cell line was established. The transformed cells had a morphology characteristic of cells tra...
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.71.2.260
更新日期:1974-02-01 00:00:00
abstract::A cDNA library prepared from human liver has been screened for factor IX (Christmas factor), a clotting factor that participates in the middle phase of blood coagulation. The library was screened with a single-stranded DNA prepared from enriched mRNA for baboon factor IX and a synthetic oligonucleotide mixture. A plas...
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.79.21.6461
更新日期:1982-11-01 00:00:00
abstract::Intact DNA molecules extracted from HSV-1 (herpes simplex virus 1, human herpes virus 1) strain MP virions have a molecular weight of approximately 97 X 10(6), but cleavage with the HinIII restriction enzyme yields fourteen fragments with summed molecular weights of 160 X 10(6). Six "major" fragments occur once in eve...
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.72.11.4243
更新日期:1975-11-01 00:00:00
abstract::The extracellular hemoglobin of Ascaris has an extremely high oxygen affinity (P50 = 0.004 mmHg). It consists of eight identical subunits of molecular weight 40,600. Their sequence, determined by protein chemistry, shows two tandemly linked globin-like sequences and an 18-residue C-terminal extension. Two N-linked gly...
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.89.10.4638
更新日期:1992-05-15 00:00:00
abstract::Ribozyme activity in vivo depends on achieving high-level expression, intracellular stability, target colocalization, and cleavage site access. At present, target site selection is problematic because of unforeseeable secondary and tertiary RNA structures that prevent cleavage. To overcome this design obstacle, we wis...
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.091411398
更新日期:2001-05-08 00:00:00
abstract::Chronic sleep deprivation perturbs the circadian clock and increases susceptibility to diseases such as diabetes, obesity, and cancer. Increased inflammation is one of the common underlying mechanisms of these diseases, thus raising a hypothesis that circadian-oscillator components may regulate immune response. Here w...
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.1209965109
更新日期:2012-07-31 00:00:00
abstract::The assembly of actin monomers into filaments and networks plays vital roles throughout eukaryotic biology, including intracellular transport, cell motility, cell division, determining cellular shape, and providing cells with mechanical strength. The regulation of actin assembly and modulation of filament mechanical p...
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.1211078109
更新日期:2012-10-16 00:00:00
abstract::We show that a drop of liquid a few hundred microns in diameter placed under a solid, elastic, thin film (∼10 μm thick) causes it to bulge by tens of microns. The deformed shape is governed by equilibrium of tensions exerted by the various interfaces and the solid film, a form of Neumann's triangle. Unlike Young's equ...
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.1304587110
更新日期:2013-06-25 00:00:00
abstract::It is not yet clear how bacterial outer membrane proteins reach their correct destination after they are secreted across the cytoplasmic membrane. We show here that porin OmpF is secreted into the medium as a water-soluble monomeric protein by spheroplasts of Escherichia coli. Furthermore, this monomeric porin is take...
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.87.2.743
更新日期:1990-01-01 00:00:00
abstract::Unconventional mRNA splicing on the endoplasmic reticulum (ER) membrane is the sole conserved mechanism in eukaryotes to transmit information regarding misfolded protein accumulation to the nucleus to activate the stress response. In metazoans, the unspliced form of X-box-binding protein 1 (XBP1u) mRNA is recruited 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.1604435113
更新日期:2016-10-04 00:00:00
abstract::The complex cooperative behavior exhibited by wild chimpanzees generates considerable theoretical and empirical interest, yet we know very little about the mechanisms responsible for its evolution. Here, we investigate the influence of kinship on the cooperative behavior of male chimpanzees living in an unusually larg...
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.0611449104
更新日期:2007-05-08 00:00:00
abstract::The locus control region of the beta-globin gene is composed of four erythroid-specific hypersensitive sites. Hypersensitive site 2 has been shown to be a powerful enhancer and contains a tandem repeat sequence for the transcription factors AP1 and NFE2 (activating protein 1 and nuclear factor erythroid 2, respectivel...
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.93.24.13943
更新日期:1996-11-26 00:00:00
abstract::A central problem in understanding enzyme regulation is to define the conformational states that account for allosteric changes in catalytic activity. For Escherichia coli aspartate transcarbamoylase (ATCase; EC) the active, relaxed (R state) holoenzyme is generally assumed to be represented by the crystal structure o...
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.090087197
更新日期:2000-05-09 00:00:00
abstract::The p2b domain of Rous sarcoma virus (RSV) Gag and the p6 domain of HIV-1 Gag contain late assembly (L) domains that engage the ESCRT membrane fission machinery and are essential for virus release. We now show that the PPXY-type RSV L domain specifically recruits the BAR domain protein PACSIN2 into virus-like particle...
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.1801849115
更新日期:2018-07-03 00:00:00
abstract::Cytochrome P450(BioI) (CYP107H1) from the biotin operon of Bacillus subtilis forms a seven-carbon diacid through a multistep oxidative cleavage of a fatty acid linked to acyl carrier protein (ACP). Crystal structures of P450(BioI) in complex with three different length fatty acyl-ACP (Escherichia coli) ligands show th...
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.0805983105
更新日期:2008-10-14 00:00:00
abstract::An argument is presented in favor of the hypothesis that, bovine carboxypeptidases A and B fit by and large, the concept of homology on the levels of both amino acid sequence and three-dimensional structure. Two peptide sequences from carboxypeptidases A and B, comprising 46 amino acid residues, display structural hom...
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.63.2.406
更新日期:1969-06-01 00:00:00
abstract::Invariant natural killer T (iNKT) cells recognize lipid antigens presented by CD1d and play a central role in regulating immunity and inflammation in peripheral tissues. However, the mechanisms which govern iNKT cell homeostasis after thymic emigration are incompletely understood. Here we demonstrate that microsomal 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.1701428114
更新日期:2017-09-26 00:00:00
abstract::Ionotropic alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors (iGluRs) mediate the majority of excitatory synaptic transmission in the CNS and are essential for the induction and maintenance of long-term potentiation and long-term depression, two cellular models of learning and memory. We identi...
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.0708699104
更新日期:2007-11-13 00:00:00
abstract::Male relationships in most species of mammals generally are characterized by intense intrasexual competition, with little bonding among unrelated individuals. In contrast, human societies are characterized by high levels of cooperation and strong bonds among both related and unrelated males. The emergence of cooperati...
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.1405811111
更新日期:2014-10-14 00:00:00
abstract::Rat liver glutamine synthetase (s(20,w) 15.0 S; MW about 352,000) resembles ovine brain glutamine synthetase in that it (a) has 8 subunits, (b) acts on both L- and D-glutamate and certain glutamate analogs (e.g., beta-glutamate, cis-cycloglutamate, and alpha-methyl-L-glutamate), and (c) is irreversibly inhibited by L-...
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.68.4.781
更新日期:1971-04-01 00:00:00
abstract::The regulation of the photosynthetic genes by DNA supercoiling in Rhodobacter capsulatus has been studied by using gyrase inhibitors in vivo and by measurement of mRNA levels of more than a dozen genes. The results demonstrate that the levels of mRNA for light-harvesting (I, II) and reaction center (L, M, H) proteins,...
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.85.12.4209
更新日期:1988-06-01 00:00:00
abstract::A-kinase anchoring proteins (AKAPs) shape second-messenger signaling responses by constraining protein kinase A (PKA) at precise intracellular locations. A defining feature of AKAPs is a helical region that binds to regulatory subunits (RII) of PKA. Mining patient-derived databases has identified 42 nonsynonymous SNPs...
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.1816614115
更新日期:2018-12-04 00:00:00
abstract::S-adenosyl-L-methionine (SAM)-dependent O-methyltransferases (OMTs) catalyze the methylation of hydroxycinnamic acid derivatives for the synthesis of methylated plant polyphenolics, including lignin. The distinction in the extent of methylation of lignins in angiosperms and gymnosperms, mediated by substrate-specific ...
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.94.10.5461
更新日期:1997-05-13 00:00:00
abstract::Lipid-soluble spin labels were incorporated into human lymphocytes and mouse L-cells and the resulting electron spin resonance spectra were compared with spectra obtained from similarly labeled human erythrocytes. Spin labels were found in all subcellular fractions of the nucleated cells that contained membranes. Spin...
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.70.1.66
更新日期:1973-01-01 00:00:00
abstract::Telomere syndromes have their most common manifestation in lung disease that is recognized as idiopathic pulmonary fibrosis and emphysema. In both conditions, there is loss of alveolar integrity, but the underlying mechanisms are not known. We tested the capacity of alveolar epithelial and stromal cells from mice with...
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.1504780112
更新日期:2015-04-21 00:00:00
abstract::cDNA clones specific for the light subunit of porcine calpain I have been isolated from a porcine kidney cDNA library. The complete primary structure of the light subunit has been revealed by nucleotide sequence analysis of the cDNA clones isolated and amino acid sequence analysis of peptides isolated from the purifie...
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.82.18.6075
更新日期:1985-09-01 00:00:00