Abstract:
:Preparations of partially purified chloroplast DNA-dependent RNA polymerase from maize and some other plants transcribe cloned chloroplast genes preferentially and much more actively from appropriately negatively supercoiled templates than from relaxed templates. We have found that the polymerase in such fractions does not bind to promoter regions of the maize chloroplast genes psbA and rbcL on small linear DNA fragments but that some protein(s) in unfractionated chloroplast extracts does bind. DEAE chromatography of the extracts has permitted the separation of a DNA-binding fraction from the bulk of the RNA polymerase activity. The binding fraction contains plastid RNA polymerase activity that is relatively independent of template topology.
journal_name
Proc Natl Acad Sci U S Aauthors
Zaitlin D,Hu J,Bogorad Ldoi
10.1073/pnas.86.3.876subject
Has Abstractpub_date
1989-02-01 00:00:00pages
876-80issue
3eissn
0027-8424issn
1091-6490journal_volume
86pub_type
杂志文章abstract::Clostridium perfringens iota-toxin (Ia) mono-ADP ribosylates Arg177 of actin, leading to cytoskeletal disorganization and cell death. To fully understand the reaction mechanism of arginine-specific mono-ADP ribosyl transferase, the structure of the toxin-substrate protein complex must be characterized. Recently, we so...
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.1217227110
更新日期:2013-03-12 00:00:00
abstract::The heme-copper oxygen reductases are redox-driven proton pumps. In the current work, the effects of mutations in a proposed exit pathway for pumped protons are examined in the ba(3)-type oxygen reductase from Thermus thermophilus, leading from the propionates of heme a(3) to the interface between subunits I and II. R...
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.1107345109
更新日期:2012-04-03 00:00:00
abstract::Besides ethanol, acetic acid is produced in naturally fermenting sweet resources and is a significant environmental stress for fruit-breeding Drosophila populations and species. Although not related to the presence of an active alcohol dehydrogenase, adult acetic acid tolerance was found to correlate with ethanol tole...
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.90.8.3621
更新日期:1993-04-15 00:00:00
abstract::Satellite tobacco necrosis virus (STNV) is one of the smallest viruses known. Its genome encodes only its coat protein (CP) subunit, relying on the polymerase of its helper virus TNV for replication. The genome has been shown to contain a cryptic set of dispersed assembly signals in the form of stem-loops that each pr...
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.1706951114
更新日期:2017-11-14 00:00:00
abstract::After more than two decades of study, many fundamental questions remain unanswered about the dynamics of glass-forming materials confined to thin films. Experiments and simulations indicate that free interfaces enhance dynamics over length scales larger than molecular sizes, and this effect strengthens at lower temper...
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.2006703117
更新日期:2020-10-13 00:00:00
abstract::Neuroinflammation is an important contributor to neuronal pathology and death in neurodegenerative diseases and neuronal injury. Therapeutic interventions blocking the activity of the inflammatory kinase IKKβ, a key regulator of neuroinflammatory pathways, is protective in several animal models of neurodegenerative di...
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.1814246116
更新日期:2019-05-28 00:00:00
abstract::Tuberculosis (TB) is a major public health problem. One-third of the world's population is estimated to be infected with Mycobacterium tuberculosis (MTB), the etiological agent causing TB, and active disease kills nearly 2 million individuals worldwide every year. Several lines of evidence indicate that interindividua...
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.1115761109
更新日期:2012-01-24 00:00:00
abstract::Protein aggregation is a complex physiological process, primarily determined by stress-related factors revealing the hidden aggregation propensity of proteins that otherwise are fully soluble. Here we report a mechanism by which glycolytic glyceraldehyde-3-phosphate dehydrogenase of Arabidopsis thaliana (AtGAPC1) is 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.1914484116
更新日期:2019-12-17 00:00:00
abstract::Signal transductions by the dual-function CXCR4 and CCR5 chemokine receptors/HIV type 1 (HIV-1) coreceptors were electrophysiologically monitored in Xenopus laevis oocytes that also coexpressed the viral receptor CD4 and a G protein-coupled inward-rectifying K+ channel (Kir 3.1). Large Kir 3.1-dependent currents gener...
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.95.14.8005
更新日期:1998-07-07 00:00:00
abstract::Sinorhizobium meliloti is an alpha-proteobacterium that forms agronomically important N(2)-fixing root nodules in legumes. We report here the complete sequence of the largest constituent of its genome, a 62.7% GC-rich 3,654,135-bp circular chromosome. Annotation allowed assignment of a function to 59% of the 3,341 pre...
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.161294398
更新日期:2001-08-14 00:00:00
abstract::Assessments of the importance of different routes of HIV-1 (HIV) transmission are vital for prioritization of control efforts. Lack of consistent direct data and large uncertainty in the risk of HIV transmission from HIV-contaminated injections has made quantifying the proportion of transmission caused by contaminated...
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.0610435104
更新日期:2007-06-05 00:00:00
abstract::Real-time visualization of intracellular calcium concentration ([Ca2+]i) changes in mammalian Purkinje cells in vitro, utilizing the dye Fura-2, indicates that calcium action potentials are generated in the dendritic tree and follow a particular activation sequence. During spontaneous oscillations or after direct curr...
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.87.13.5084
更新日期:1990-07-01 00:00:00
abstract::Staphylococcus aureus is a leading cause of both nosocomial and community-acquired infection. Biofilm formation at the site of infection reduces antimicrobial susceptibility and can lead to chronic infection. During biofilm formation, a subset of cells liberate cytoplasmic proteins and DNA, which are repurposed to for...
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.1704544114
更新日期:2017-07-18 00:00:00
abstract::Asymmetric cell division (ACD) is believed to be a physiological event that occurs during development and tissue homeostasis in a large variety of organisms. ACD produces two unequal daughter cells, one of which resembles a multipotent stem and/or progenitor cell, whereas the other has potential for differentiation. 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.1205525109
更新日期:2012-10-30 00:00:00
abstract::The protein encoded by the GAL4 gene of the yeast Saccharomyces cerevisiae binds to DNA upstream of several genes and activates transcription. To try to understand these processes, we have undertaken a genetic analysis of GAL4. Here we report that nearly all missense mutations in GAL4, selected in vivo to lack functio...
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.84.8.2401
更新日期:1987-04-01 00:00:00
abstract::Defining bacterial species remains a challenging problem even for the model bacterium Escherichia coli and has major practical consequences for reliable diagnosis of infectious disease agents and regulations for transport and possession of organisms of economic importance. E. coli traditionally is thought to live 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.1015622108
更新日期:2011-04-26 00:00:00
abstract::Ferredoxin was isolated from individual Leucaena glauca trees, and the distribution of amino acids at three of the four sites of sequence heterogeneity was determined. The results indicated that the most probable causes of the observed microheterogeneity are the presence of either nonallelic nuclear genes or differing...
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.63.4.1269
更新日期:1969-08-01 00:00:00
abstract::A common challenge in pathogen discovery by deep sequencing approaches is to recognize viral or subviral pathogens in samples of diseased tissue that share no significant homology with a known pathogen. Here we report a homology-independent approach for discovering viroids, a distinct class of free circular RNA subvir...
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.1117815109
更新日期:2012-03-06 00:00:00
abstract::Although current theories of color vision differ in many respects, they all assume the existence of a uniquely defined neutral point in chromaticity space. It generally is assumed that this point satisfies several criteria simultaneously. One of these criteria is that it is perceived as achromatic. A further criterion...
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.192216699
更新日期:2002-10-01 00:00:00
abstract::Structural differences between dynein and kinesin suggest a unique molecular mechanism of dynein motility. Measuring the mechanical properties of a single molecule of dynein is crucial for revealing the mechanisms underlying its movement. We measured the step size and force produced by single molecules of active cytop...
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.0508511103
更新日期:2006-04-11 00:00:00
abstract::For study of the basis of an X-linked form of gout in man, several clonal lines deficient in hypoxanthine-guanine phosphoribosyltransferase (EC 2.4.2.8) were selected from the human lymphoblast line WI-L2 by spontaneous and mutagen-induced resistance to 10 muM 8-azaguanine. Three groups could be defined: (1) clones wi...
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.71.7.2679
更新日期:1974-07-01 00:00:00
abstract::While we have come to appreciate the architectural complexity of microbially synthesized secondary metabolites, far less attention has been paid to linking their structural features with possible modes of action. This is certainly the case with tropodithietic acid (TDA), a broad-spectrum antibiotic generated by marine...
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.1518034113
更新日期:2016-02-09 00:00:00
abstract::NKp46 is a cell surface receptor expressed on natural killer (NK) cells, on a minute subset of T cells, and on a population of innate lymphoid cells that produce IL-22 and express the transcription factor retinoid-related orphan receptor (ROR)-γt, referred to as NK cell receptor (NKR)(+)ROR-γt(+) cells. Here we descri...
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.1112064108
更新日期:2011-11-08 00:00:00
abstract::Positive allosteric modulation of the mu-opioid receptor (MOPr), the site of action of all clinically used opioids, represents a potential approach for the management of pain. We recently reported on positive allosteric modulators of MOPr (mu-PAMs), a class A G protein coupled receptor (GPCR). This study was designed ...
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.1415013111
更新日期:2014-12-23 00:00:00
abstract::We have previously demonstrated in a series of searches for antithrombotic agents that diadenosine 5',5"'-P1,P4-tetraphosphate (AppppA) and its analogues are competitive inhibitors of ADP-induced platelet aggregation. Among various analogues, the P2,P3-monochloromethylene analog of AppppA (AppCHClppA) is superior to u...
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.94.8.4034
更新日期:1997-04-15 00:00:00
abstract::We have investigated the differentiation potential of precursor cells within the developing spinal cord of mice and have shown that spinal cord cells from embryonic day 10 specifically give rise to neurons when plated onto an astrocytic monolayer, Ast-1. These neurons had the morphology of motor neurons and > 83% expr...
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.92.22.10079
更新日期:1995-10-24 00:00:00
abstract::Virus population growth depends on contacts between viruses and their hosts. It is often unclear how sufficient contacts are made between viruses and their specific hosts to generate spikes in viral abundance. Here, we show that copepods, acting as predators, can bring aquatic viruses and their algal hosts into contac...
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.1613843113
更新日期:2016-11-29 00:00:00
abstract::Morphine produces analgesia at opiate receptors expressed in nociceptive circuits. mu, delta, and kappa opiate receptor subtypes are expressed in circuits that can modulate nociception and receive inputs from endogenous opioid neuropeptide ligands. The roles played by each receptor subtype in nociceptive processing in...
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.94.4.1544
更新日期:1997-02-18 00:00:00
abstract::A remote labeling method has been developed to determine (18)O kinetic isotope effects (KIEs) in Ras-catalyzed GTP hydrolysis. Substrate mixtures consist of (13)C-depleted GTP and [(18)O,(13)C]GTP that contains (18)O at phosphoryl positions of mechanistic interest and (13)C at all carbon positions of the guanosine moi...
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.0401675101
更新日期:2004-06-15 00:00:00
abstract::We have isolated a cold-sensitive mutant of Saccharomyces cerevisiae in which there is a deficit of 60S ribosomal subunits. Cold sensitivity and the assembly defect are recessive and cosegregate, defining a single essential gene that we designated DRS1 (deficiency of ribosomal subunits). The wild-type DRS1 gene was cl...
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.89.23.11131
更新日期:1992-12-01 00:00:00