The peptide-catalyzed stereospecific synthesis of tetroses: a possible model for prebiotic molecular evolution.

abstract：:Cell-free extracts of nifF and nifJ mutants of Klebsiella pneumoniae are unable to couple acetylene reduction (N2 fixation) by nitrogenase to the oxidation of organic metabolites. However, nifF and nifJ mutants can complement each other in vitro to establish the coupling. This indicates that the products of the nifF a...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Nieva-Gómez D,Roberts GP,Klevickis S,Brill WJ

更新日期：1980-05-01 00:00:00

abstract：:Food choices are shifting globally in ways that are negatively affecting both human health and the environment. Here we consider how consuming an additional serving per day of each of 15 foods is associated with 5 health outcomes in adults and 5 aspects of agriculturally driven environmental degradation. We find that ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Clark MA,Springmann M,Hill J,Tilman D

更新日期：2019-11-12 00:00:00

abstract：:The matrix-2 (M2) protein from influenza A virus is a tetrameric, integral transmembrane (TM) protein that plays a vital role in viral replication by proton flux into the virus. The His37 tetrad is a pH sensor in the center of the M2 TM helix that activates the channel in response to the low endosomal pH. M2 consists ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Torabifard H,Panahi A,Brooks CL 3rd

更新日期：2020-02-18 00:00:00

abstract：:Bipolar-cell axon terminals receive direct synaptic input from amacrine-cell processes, suggesting a possible pathway for modulation of transmitter release. In retinal slices, bath-applied baclofen, a gamma-aminobutyrate type B (GABAB) receptor agonist, reduced a patch-clamp-recorded L-type calcium channel current in ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Maguire G,Maple B,Lukasiewicz P,Werblin F

更新日期：1989-12-01 00:00:00

abstract：:Direct structural insights on the fundamental mechanisms of permeation, selectivity, and gating remain unavailable for the Na(+) and Ca(2+) channel families. Here, we report the spectroscopic structural characterization of the isolated Voltage-Sensor Domain (VSD) of the prokaryotic Na(+) channel NaChBac in a lipid bil...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Chakrapani S,Sompornpisut P,Intharathep P,Roux B,Perozo E

更新日期：2010-03-23 00:00:00

abstract：:Circadian rhythms modulate many aspects of physiology. Knowledge of the molecular basis of these rhythms has exploded in the last 20 years. However, most of these data are from model organisms, and translation to clinical practice has been limited. Here, we present an approach to identify molecular rhythms in humans f...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Anafi RC,Francey LJ,Hogenesch JB,Kim J

更新日期：2017-05-16 00:00:00

abstract：:Natural resistance-associated macrophage protein (Nramp) family transporters catalyze uptake of essential divalent transition metals like iron and manganese. To discriminate against abundant competitors, the Nramp metal-binding site should favor softer transition metals, which interact either covalently or ionically w...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Bozzi AT,Bane LB,Weihofen WA,McCabe AL,Singharoy A,Chipot CJ,Schulten K,Gaudet R

更新日期：2016-09-13 00:00:00

abstract：:125I-Labeled L-fucose-albumin complex and rat preputial beta-glucuronidase are rapidly cleared from plasma after intravenous infusion. L-Fucose-albumin retards the plasma clearance of beta-glucuronidase whereas D-fucose-albumin is inactive. In vitro, 125I-labeled L-fucose-albumin is taken up into rat or rabbit alveola...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Shepherd VL,Lee YC,Schlesinger PH,Stahl PD

更新日期：1981-02-01 00:00:00

abstract：:Type IV pili are thin filaments that extend from the poles of a diverse group of bacteria, enabling them to move at speeds of a few tenths of a micrometer per second. They are required for twitching motility, e.g., in Pseudomonas aeruginosa and Neisseria gonorrhoeae, and for social gliding motility in Myxococcus xanth...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Skerker JM,Berg HC

更新日期：2001-06-05 00:00:00

abstract：:Secretion of extracellular polymeric substances (EPSs) by growing bacteria is an integral part of forming biofilm-like structures. In such dense systems, mechanical interactions among the structural components can be expected to significantly contribute to morphological properties. Here, we use a particle-based modeli...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Ghosh P,Mondal J,Ben-Jacob E,Levine H

更新日期：2015-04-28 00:00:00

abstract：:The ubiquitin-conjugating enzyme Ubc13 mediates lysine-63-specific protein ubiquitination involved in signal transduction by immune receptors; however, the in vivo physiological functions of Ubc13 remain incompletely understood. Using Ubc13 conditional knockout mice, we show that somatic deletion of the Ubc13 gene cau...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Wu X,Yamamoto M,Akira S,Sun SC

更新日期：2009-12-08 00:00:00

abstract：:Proteins need to be tightly regulated as they control biological processes in most normal cellular functions. The precise mechanisms of regulation are rarely completely understood but can involve binding of endogenous ligands and/or partner proteins at specific locations on a protein that can modulate function. Often,...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Ludlow RF,Verdonk ML,Saini HK,Tickle IJ,Jhoti H

更新日期：2015-12-29 00:00:00

abstract：:A vaccinia virus host range mutant (hr mutant) deleted of 18 kilobase pairs at the left end of the genome has been employed to precisely map a viral gene required for multiplication in human cells. DNA fragments from the wild-type virus were inserted into the thymidine kinase gene of mutant virus by means of in vivo h...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Gillard S,Spehner D,Drillien R,Kirn A

更新日期：1986-08-01 00:00:00

abstract：:The highly aggressive character of melanoma makes it an excellent model for probing the mechanisms underlying metastasis, which remains one of the most difficult challenges in treating cancer. We find that miR-182, member of a miRNA cluster in a chromosomal locus (7q31-34) frequently amplified in melanoma, is commonly...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Segura MF,Hanniford D,Menendez S,Reavie L,Zou X,Alvarez-Diaz S,Zakrzewski J,Blochin E,Rose A,Bogunovic D,Polsky D,Wei J,Lee P,Belitskaya-Levy I,Bhardwaj N,Osman I,Hernando E

更新日期：2009-02-10 00:00:00

abstract：:Retinoic acid is a morphogenetic signaling molecule derived from vitamin A and involved in vertebrate development. Two groups of receptors, retinoic acid receptors and retinoid X receptors (RXRs), have been identified. All-trans-retinoic acid is the high-affinity ligand for retinoic acid receptors, and 9-cis-retinoic ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Yang Y,Vacchio MS,Ashwell JD

更新日期：1993-07-01 00:00:00

abstract：:We show that it is possible to direct particles entrained in a fluid along trajectories much like rays of light in classical optics. A microstructured, asymmetric post array forms the core hydrodynamic element and is used as a building block to construct microfluidic metamaterials and to demonstrate refractive, focusi...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Morton KJ,Loutherback K,Inglis DW,Tsui OK,Sturm JC,Chou SY,Austin RH

更新日期：2008-05-27 00:00:00

abstract：:Aggregation of p53 is initiated by first-order processes that generate an aggregation-prone state with parallel pathways of major or partial unfolding. Here, we elaborate the mechanism and explore its consequences, beginning with the core domain and extending to the full-length p53 mutant Y220C. Production of large li...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Wang G,Fersht AR

更新日期：2012-08-21 00:00:00

abstract：:Ultraviolet irradiation of the [3H]colchicine-tubulin complex leads to direct photolabeling of tubulin with low but practicable efficiency. The bulk (70% to greater than 90%) of the labeling occurs on beta-tubulin and appears early after irradiation, whereas alpha-tubulin is labeled later. The labeling ratio of beta-t...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Wolff J,Knipling L,Cahnmann HJ,Palumbo G

更新日期：1991-04-01 00:00:00

abstract：:We have characterized seven murine retinoic acid receptor gamma cDNA isoforms (mRAR-gamma 1 to -gamma 7) generated by alternative splicing of at least seven exons. These isoforms differ from one another in their 5' untranslated region and in two cases (mRAR-gamma 1 and -gamma 2) differ in their N-terminal A region, wh...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Kastner P,Krust A,Mendelsohn C,Garnier JM,Zelent A,Leroy P,Staub A,Chambon P

更新日期：1990-04-01 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

authors： Tate SS,Meister A

更新日期：1971-04-01 00:00:00

abstract：:The mechanism by which antifreeze proteins (AFPs) irreversibly bind to ice has not yet been resolved. The ice-binding site of an AFP is relatively hydrophobic, but also contains many potential hydrogen bond donors/acceptors. The extent to which hydrogen bonding and the hydrophobic effect contribute to ice binding has ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Garnham CP,Campbell RL,Davies PL

更新日期：2011-05-03 00:00:00

abstract：:The kainate receptor (KAR), a subtype of glutamate receptor, mediates excitatory synaptic responses at a subset of glutamatergic synapses. However, the molecular mechanisms underlying the trafficking of its different subunits are poorly understood. Here we use the CA1 hippocampal pyramidal cell, which lacks KAR-mediat...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Sheng N,Shi YS,Nicoll RA

更新日期：2017-01-31 00:00:00

abstract：:A 60,000-dalton polypeptide (p60) has been identified in the feline leukemia virus (FeLV) pseudotype of Moloney sarcoma virus [MSV(FeLV)]. This polypeptide is present in the purified virus complex in concentrations greater than either the murine p30 or the feline p27. Purified p60 crossreacts immunologically with muri...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Oskarsson MK,Robey WG,Harris CL,Fischinger PJ,Haapala DK,Vande Woude GF

更新日期：1975-06-01 00:00:00

abstract：:Extraction of thylakoid membranes with cholate in the presence of ammonium sulfate inactivated oxygen evolution and liberated a managanese-containing protein. This protein could be combined with preformed liposomes containing the depleted thylakoid membranes to restore 85% of the original oxygen-evolution activity. Th...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Spector M,Winget GD

更新日期：1980-02-01 00:00:00

abstract：:The response of nerve cells to synaptic inputs and the propagation of this activation is critically dependent on the cell-surface distribution of ion channels. In the hippocampus, Ca2+ influx through N-methyl-D-aspartate receptors (NMDAR) and/or voltage-dependent calcium channels on dendrites is thought to be critical...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Benke TA,Jones OT,Collingridge GL,Angelides KJ

更新日期：1993-08-15 00:00:00

abstract：:Geckos can run rapidly on walls and ceilings, requiring high friction forces (on walls) and adhesion forces (on ceilings), with typical step intervals of approximately 20 ms. The rapid switching between gecko foot attachment and detachment is analyzed theoretically based on a tape model that incorporates the adhesion ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Tian Y,Pesika N,Zeng H,Rosenberg K,Zhao B,McGuiggan P,Autumn K,Israelachvili J

更新日期：2006-12-19 00:00:00

abstract：:Intrinsically disordered proteins (IDPs) and their conformational transitions play an important role in neurotransmitter release at the neuronal synapse. Here, the SNARE proteins are essential by forming the SNARE complex that drives vesicular membrane fusion. While it is widely accepted that the SNARE proteins are in...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Lakomek NA,Yavuz H,Jahn R,Pérez-Lara Á

更新日期：2019-04-30 00:00:00

abstract：:The molecular nature of the cell surface-cytoskeleton interaction in microvilli isolated from ascites 13762 rat mammary adenocarcinoma sublines with immobile (MAT-C1) and mobile (MAT-B1) receptors was investigated by extraction and fractionation studies on the microvillar membranes. Extraction of membranes from MAT-C1...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Carraway CA,Jung G,Carraway KL

更新日期：1983-01-01 00:00:00

abstract：:Invariant natural killer T (iNKT) cells recognize self lipid antigens presented by CD1d molecules. The nature of the self-antigens involved in the development and maturation of iNKT cells is poorly defined. Lysophospholipids are self-antigens presented by CD1d that are generated through the action of phospholipases A1...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Paduraru C,Bezbradica JS,Kunte A,Kelly R,Shayman JA,Veerapen N,Cox LR,Besra GS,Cresswell P

更新日期：2013-03-26 00:00:00

abstract：:DNA-membrane attachment in cultures of E. coli B/r is found to depend on the pattern of DNA synthesis, (a) When the number of replication points increases, the fraction of the DNA that is membrane bound also increases. The relationship between the amount of DNA-membrane attachment and the number of replication points ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Parker DL,Glaser DA

更新日期：1975-06-01 00:00:00