Abstract:
:An Escherichia coli chromosomal DNA fragment cloned on a multicopy plasmid conferred resistance to carbonylcyanide m-chlorophenylhydrazone, nalidixic acid, and a number of other toxic compounds. The sequence of the cloned emr locus located at minute 57.5 of the chromosome revealed two open reading frames, emrA and emrB. emrB encodes a highly hydrophobic 56.2-kDa peptide, with 14 potential alpha-helices to span the inner membrane. The peptide is homologous to QacA, a multidrug-resistant pump from Staphylococcus aureus, and belongs to a gene family that includes tetracycline-resistant pumps of Gram-positive bacteria and the galactose/H+ symporter of E. coli. emrA encodes a putative 42.7-kDa peptide containing a single hydrophobic domain and a large C-terminal hydrophilic domain. An active pho-fusion to the C domain suggested that EmrA is a membrane protein. Disruption of emrB significantly increased sensitivity of cells to uncouplers. The cellular content of uncoupler increased in the order: overexpressed emrB cells greater than wild type greater than emrB-.
journal_name
Proc Natl Acad Sci U S Aauthors
Lomovskaya O,Lewis Kdoi
10.1073/pnas.89.19.8938keywords:
subject
Has Abstractpub_date
1992-10-01 00:00:00pages
8938-42issue
19eissn
0027-8424issn
1091-6490journal_volume
89pub_type
杂志文章abstract::A single dose of N-methyl-N-nitrosourea given to sexually immature female Buf/N rats produces a high incidence of mammary adenocarcinomas. A large percentage of these tumors contain the Ha-ras oncogene, activated by a G----A transition at the second nucleotide of codon 12. Copenhagen rats, on the other hand, are compl...
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.89.3.1001
更新日期:1992-02-01 00:00:00
abstract::We developed a method for rapidly generating thermostable enzyme variants. Our strategy is to introduce the gene coding for a given enzyme from a mesophilic organism into a thermophile, Bacillus stearothermophilus. Variants that retain the enzymatic activity at the higher growth temperatures of the thermophile are the...
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.83.3.576
更新日期:1986-02-01 00:00:00
abstract::Brain-derived neurotrophic factor (BDNF), a cognate ligand for the tyrosine kinase receptor B (TrkB) receptor, mediates neuronal survival, differentiation, synaptic plasticity, and neurogenesis. However, BDNF has a poor pharmacokinetic profile that limits its therapeutic potential. Here we report the identification of...
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.0913572107
更新日期:2010-02-09 00:00:00
abstract::Protein kinase P (PK-P) activated by histones or certain other basic compounds has been purified previously from yeast [Yanagita, Y., Abdel-Ghany, M., Raden, D., Nelson, N. & Racker, E. (1987) Proc. Natl. Acad. Sci. USA 84, 925-929]. It is shown here that PK-P is present in solubilized membranes of A-431 carcinoma cel...
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.84.24.8888
更新日期:1987-12-01 00:00:00
abstract::A muscarone-binding material has been found in Torpedo electroplax. The material behaves in several ways as one would expect of the binding component of the acetylcholine receptor, especially in its high affinity for muscarone (approximate K = 7 x 10(-6)M), acetylcholine (approximate K = 1.1 x 10(-6)M), curare, and ni...
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.63.2.496
更新日期:1969-06-01 00:00:00
abstract::When purified dimers of hemagglutinin-neuraminidase molecules released by protease digestion from three strains of human parainfluenza virus 1 were used in crystallization trials, long thin needle crystals formed. Electron microscopic analysis of these needle crystals revealed that they are composed of stacks of tripl...
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.90.4.1523
更新日期:1993-02-15 00:00:00
abstract::Charcot-Marie-Tooth disease type 4C (CMT4C) is an early-onset, autosomal recessive form of demyelinating neuropathy. The clinical manifestations include progressive scoliosis, delayed age of walking, muscular atrophy, distal weakness, and reduced nerve conduction velocity. The gene mutated in CMT4C disease, SH3TC2/KIA...
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.0905523106
更新日期:2009-10-13 00:00:00
abstract::Listeriolysin O (LLO) is a cholesterol-dependent cytolysin that is an essential virulence factor of Listeria monocytogenes. LLO pore-forming activity is pH-dependent; it is active at acidic pH (<6), but not at neutral pH. In contrast to other pH-dependent toxins, we have determined that LLO pore-forming activity is 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.0500558102
更新日期:2005-08-30 00:00:00
abstract::The bacterial pathogen Shigella flexneri causes bacillary dysentery in humans by invading coloncytes. Upon contact with epithelial cells, S. flexneri elicits localized plasma membrane projections sustained by long actin filaments which engulf the microorganism. The products necessary for Shigella entry include three s...
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.93.3.1254
更新日期:1996-02-06 00:00:00
abstract::The major small nuclear ribonucleoproteins (snRNPs) U1, U2, U4/U6, and U5 share a set of common proteins denoted B/B', D1, D2, D3, E, F, and G which play an important part in the biogenesis of the snRNPs. In addition, there is a link between the common proteins and autoimmunity; the three D proteins, together with B/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.91.25.12317
更新日期:1994-12-06 00:00:00
abstract::Cell walls of Mycobacterium leprae, prepared by differential solvent extraction, were shown to contain arabinogalactan, mycolates, and peptidoglycan. In addition, amino acid analysis revealed the unexpected presence of large amounts of protein that retained potent immunological reactivity. Purified cell walls stimulat...
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.85.6.1917
更新日期:1988-03-01 00:00:00
abstract::Current issues pertaining to theoretical simulations of materials, with a focus on systems of nanometer-scale dimensions, are discussed. The use of atomistic simulations as high-resolution numerical experiments, enabling and guiding formulation and testing of analytic theoretical descriptions, is demonstrated through ...
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.0408038102
更新日期:2005-05-10 00:00:00
abstract::High molecular weight polypeptides (HMWPs) of 270,000 to 340,000 were found to be major components of intermediate filaments prepared by Triton X-100 extraction after spreading of rat glioma C6, HeLa, Chinese hamster ovary, and simian virus 40-transformed Chinese hamster lung cells. C6 HMWPs were shown to resemble hig...
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.77.8.4808
更新日期:1980-08-01 00:00:00
abstract::When two phases of water are at equilibrium, the ratio of hydrogen isotopes in each is slightly altered because of their different phase affinities. This isotopic fractionation process can be utilized to analyze water's movement in the world's climate. Here we show that equilibrium fractionation ratios, an entirely qu...
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.1203365109
更新日期:2012-05-22 00:00:00
abstract::Transmural stimulation of the isolated adrenal gland of the rat and guinea pig results in secretion of catecholamine. The secretion is due to activation of cholinergic receptors of the adrenal medulla by acetylcholine released from splanchnic nerve terminals after transmural stimulation. Our aim was to see whether the...
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.79.9.3071
更新日期:1982-05-01 00:00:00
abstract::The recent success of antibody-drug conjugates (ADCs) in the treatment of cancer has led to a revived interest in microtubule-destabilizing agents. Here, we determined the high-resolution crystal structure of the complex between tubulin and maytansine, which is part of an ADC that is approved by the US Food and Drug 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.1408124111
更新日期:2014-09-23 00:00:00
abstract::REPRESSOR OF SILENCING 1 (ROS1) is a DNA demethylation enzyme that was previously identified during a genetic screen for the silencing of both RD29A-LUC and 35S-NPTII transgenes on a T-DNA construct. Here we performed a genetic screen to identify additional mutants in which the 35S-NPTII transgene is silenced. We iden...
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.1208557109
更新日期:2012-07-10 00:00:00
abstract::Murine hematopoietic blast colony-forming cells (BL-CFCs) are able to generate up to 30,000 progeny blast cells within 10 d in agar cultures. Contained in these populations are large numbers of lineage-committed progenitor cells in the granulocytic and macrophage lineages. Sequential analyses of blast colonies reveale...
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.1011881107
更新日期:2010-09-14 00:00:00
abstract::The in vivo production of frameshift and base-substitution mutations predicted as a consequence of the metabolic processing of misaligned quasipalindromic DNA sequences has been confirmed. Spontaneous frameshift mutations of the T4 rII gene that had been genetically mapped to quasipalindromic DNA sequences were sequen...
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.81.17.5528
更新日期:1984-09-01 00:00:00
abstract::Animals treated with potent gamma-glutamyl transpeptidase inhibitors and a patient with severe gamma-glutamyl transpeptidase deficiency excrete much larger than normal amounts of glutathione, gamma-glutamylcysteine, and cysteine in their urine; these compounds were found in disulfide forms. The findings indicate that ...
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.77.6.3384
更新日期:1980-06-01 00:00:00
abstract::Replication of the kinetoplast DNA (kDNA) minicircle of trypanosomatids initiates at a conserved 12-nt sequence, 5'-GGGGTTGGTGTA-3', termed the universal minicircle sequence (UMS). A sequence-specific single-stranded DNA-binding protein from Crithidia fasciculata binds the heavy strand of the 12-mer UMS. Whereas this ...
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.92.23.10511
更新日期:1995-11-07 00:00:00
abstract::A transformation-defective mutant of Abelson murine leukemia virus (A-MuLV), called A-MuLV-P92td, has been isolated. The mutant encodes a serologically identifiable A-MuLV protein of molecular weight 92,000 (P92) but it lacks the ability to transform either fibroblasts or bone marrow lymphoid cells. In contrast to the...
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.77.8.4993
更新日期:1980-08-01 00:00:00
abstract::An exact treatment of adsorption from a one-dimensional lattice gas is used to eliminate and correct a well-known inconsistency in the Brunauer-Emmett-Teller (B.E.T.) equation-namely, Gibbs excess adsorption is not taken into account and the Gibbs integral diverges at the transition point. However, neither model shoul...
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.93.25.14328
更新日期:1996-12-10 00:00:00
abstract::Using morphometrical methods, we investigated variation in the skeletons of more than 400 offspring of C57BL/6J and DBA/2J male mice that had received either a 250 mg/kg dose of the mutagen ethylnitrosourea or a solvent control. Sperm involved in the matings developed from cells in the spermatogonial stage at the time...
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.82.9.2852
更新日期:1985-05-01 00:00:00
abstract::Leptin is an adipocytokine that plays a key role in the modulation of immune responses and the development and maintenance of inflammation. Circulating levels of leptin are elevated in systemic lupus erythematosus (SLE) patients, but it is not clear whether this association can reflect a direct influence of leptin on ...
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.1607101113
更新日期:2016-09-20 00:00:00
abstract::Streptococcus groups A and B cause serious infections, including early onset sepsis and meningitis in newborns. Rib domain-containing surface proteins are found associated with invasive strains and elicit protective immunity in animal models. Yet, despite their apparent importance in infection, the structure of the Ri...
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.1911776116
更新日期:2019-12-09 00:00:00
abstract::It is a well known fact that stirring keeps particles suspended in fluids. This is apparent, for instance, when shaking medicine flasks, when agitating tea deposits in a mug, or when heavy winds fill the air with dust particles. The commonplace nature of such observations makes it easy to accept that this feature will...
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.0401539101
更新日期:2004-12-21 00:00:00
abstract::Ectopic expression of transcription factors can reprogram somatic cells to a pluripotent state. However, most of the studies used skin fibroblasts as the starting population for reprogramming, which usually take weeks for expansion from a single biopsy. We show here that induced pluripotent stem (iPS) cells can be gen...
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.0908450106
更新日期:2009-09-15 00:00:00
abstract::The early steps in the biosynthesis of Taxol involve the cyclization of geranylgeranyl diphosphate to taxa-4(5),11(12)-diene followed by cytochrome P450-mediated hydroxylation at C5, acetylation of this intermediate, and a second cytochrome P450-dependent hydroxylation at C10 to yield taxadien-5 alpha-acetoxy-10 beta-...
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.98.4.1501
更新日期:2001-02-13 00:00:00
abstract::The chemosmotic model provides a framework for visualizing energy-coupled reactions (vectorial reaction sequences, membrane-dependent gradient formation, and charge separation of reacting species) and a mechanism for energy coupling (indirect coupling between the driving and driven reaction sequences mediated by a mem...
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.78.4.2240
更新日期:1981-04-01 00:00:00