ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    facet.materialart.
    Unknown
    Copper-catalyzed aerobic oxidative coupling: From ketone and diamine to pyrazine (2015)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2015-10-11
    Description: Copper-catalyzed aerobic oxidative C–H/N–H coupling between simple ketones and diamines was developed toward the synthesis of a variety of pyrazines. Various substituted ketones were compatible for this transformation. Preliminary mechanistic investigations indicated that radical species were involved. X-ray absorption fine structure experiments elucidated that the Cu(II) species 5 coordinated by two N atoms at a distance of 2.04 Å and two O atoms at a shorter distance of 1.98 Å was a reactive one for this aerobic oxidative coupling reaction. Density functional theory calculations suggested that the intramolecular coupling of cationic radicals was favorable in this transformation.
    Electronic ISSN: 2375-2548
    Topics: Natural Sciences in General
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 2
    facet.materialart.
    Unknown
    Ligand-triggered allosteric ADP release primes a plant NLR complex (2019)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2019
    Description: 〈p〉Pathogen recognition by nucleotide-binding (NB), leucine-rich repeat (LRR) receptors (NLRs) plays roles in plant immunity. The 〈i〉Xanthomonas campestris〈/i〉 pv.〈i〉 campestris〈/i〉 effector AvrAC uridylylates the 〈i〉Arabidopsis〈/i〉 PBL2 kinase, and the latter (PBL2〈sup〉UMP〈/sup〉) acts as a ligand to activate the NLR ZAR1 precomplexed with the RKS1 pseudokinase. Here we report the cryo–electron microscopy structures of ZAR1-RKS1 and ZAR1-RKS1-PBL2〈sup〉UMP〈/sup〉 in an inactive and intermediate state, respectively. The ZAR1〈sup〉LRR〈/sup〉 domain, compared with animal NLR〈sup〉LRR〈/sup〉 domains, is differently positioned to sequester ZAR1 in an inactive state. Recognition of PBL2〈sup〉UMP〈/sup〉 is exclusively through RKS1, which interacts with ZAR1〈sup〉LRR〈/sup〉. PBL2〈sup〉UMP〈/sup〉 binding stabilizes the RKS1 activation segment, which sterically blocks ZAR1 adenosine diphosphate (ADP) binding. This engenders a more flexible NB domain without conformational changes in the other ZAR1 domains. Our study provides a structural template for understanding plant NLRs.〈/p〉
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 3
    facet.materialart.
    Unknown
    Parallel Sites Implicate Functional Convergence of the Hearing Gene Prestin among Echolocating Mammals (2014)
    Oxford University Press
    Details
    Publication Date: 2014-08-20
    Description: Echolocation is a sensory system whereby certain mammals navigate and forage using sound waves, usually in environments where visibility is limited. Curiously, echolocation has evolved independently in bats and whales, which occupy entirely different environments. Based on this phenotypic convergence, recent studies identified several echolocation-related genes with parallel sites at the protein sequence level among different echolocating mammals, and among these, prestin seems the most promising. Although previous studies analyzed the evolutionary mechanism of prestin , the functional roles of the parallel sites in the evolution of mammalian echolocation are not clear. By functional assays, we show that a key parameter of prestin function, 1/ α , is increased in all echolocating mammals and that the N7T parallel substitution accounted for this functional convergence. Moreover, another parameter, V 1/2 , was shifted toward the depolarization direction in a toothed whale, the bottlenose dolphin ( Tursiops truncatus ) and a constant-frequency (CF) bat, the Stoliczka’s trident bat ( Aselliscus stoliczkanus ). The parallel site of I384T between toothed whales and CF bats was responsible for this functional convergence. Furthermore, the two parameters (1/ α and V 1/2 ) were correlated with mammalian high-frequency hearing, suggesting that the convergent changes of the prestin function in echolocating mammals may play important roles in mammalian echolocation. To our knowledge, these findings present the functional patterns of echolocation-related genes in echolocating mammals for the first time and rigorously demonstrate adaptive parallel evolution at the protein sequence level, paving the way to insights into the molecular mechanism underlying mammalian echolocation.
    Print ISSN: 0737-4038
    Electronic ISSN: 1537-1719
    Topics: Biology
    Published by Oxford University Press
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 4
    facet.materialart.
    Unknown
    MIWI2 targets RNAs transcribed from piRNA-dependent regions to drive DNA methylation in mouse prospermatogonia (2018)
    Springer Nature
    Details
    Publication Date: 2018
    Description: 〈p〉Argonaute/Piwi proteins can regulate gene expression via RNA degradation and translational regulation using small RNAs as guides. They also promote the establishment of suppressive epigenetic marks on repeat sequences in diverse organisms. In mice, the nuclear Piwi protein MIWI2 and Piwi-interacting RNAs (piRNAs) are required for DNA methylation of retrotransposon sequences and some other sequences. However, its underlying molecular mechanisms remain unclear. Here, we show that piRNA-dependent regions are transcribed at the stage when piRNA-mediated DNA methylation takes place. MIWI2 specifically interacts with RNAs from these regions. In addition, we generated mice with deletion of a retrotransposon sequence either in a representative piRNA-dependent region or in a piRNA cluster. Both deleted regions were required for the establishment of DNA methylation of the piRNA-dependent region, indicating that piRNAs determine the target specificity of MIWI2-mediated DNA methylation. Our results indicate that MIWI2 affects the chromatin state through base-pairing between piRNAs and nascent RNAs, as observed in other organisms possessing small RNA-mediated epigenetic regulation.〈/p〉
    Print ISSN: 0261-4189
    Electronic ISSN: 1460-2075
    Topics: Biology , Medicine
    Published by Springer Nature on behalf of The European Molecular Biology Organization (EMBO).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 5
    facet.materialart.
    Unknown
    Genomic and functional evidence reveals molecular insights into the origin of echolocation in whales (2018)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2018
    Description: 〈p〉Echolocation allows toothed whales to adapt to underwater habitats where vision is ineffective. Because echolocation requires the ability to detect exceptional high-frequency sounds, fossils related to the auditory system can help to pinpoint the origin of echolocation in whales. However, because of conflicting interpretations of archaeocete fossils, when and how whales evolved the high-frequency hearing correlated with echolocation remain unclear. We address these questions at the molecular level by systematically investigating the convergent evolution of 7206 orthologs across 16 mammals and find that convergent genes between the last common ancestor of all whales (LCAW) and echolocating bats are not significantly enriched in functional categories related to hearing, and that convergence in hearing-related proteins between them is not stronger than that between nonecholocating mammalian lineages and echolocating bats. However, these results contrast with those of parallel analyses between the LCA of toothed whales (LCATW) and echolocating bats. Furthermore, we reconstruct the ancestral genes for the hearing protein 〈i〉prestin〈/i〉 for the LCAW and LCATW; we show that the LCAW 〈i〉prestin〈/i〉 exhibits the same function as that of nonecholocating mammals, but the LCATW 〈i〉prestin〈/i〉 shows functional convergence with that of extant echolocating mammals. Mutagenesis shows that functional convergence of prestin is driven by convergent changes in the prestins S392A and L497M in the LCATW and echolocating bats. Our results provide genomic and functional evidence supporting the origin of high-frequency hearing in the LCAW, not the LCATW, and reveal molecular insights into the origin and evolutionary trajectories of echolocation in whales.〈/p〉
    Electronic ISSN: 2375-2548
    Topics: Natural Sciences in General
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 6
    facet.materialart.
    Unknown
    DNA RECOMBINATION. Base triplet stepping by the Rad51/RecA family of recombinases (2015)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2015-09-01
    Description: DNA strand exchange plays a central role in genetic recombination across all kingdoms of life, but the physical basis for these reactions remains poorly defined. Using single-molecule imaging, we found that bacterial RecA and eukaryotic Rad51 and Dmc1 all stabilize strand exchange intermediates in precise three-nucleotide steps. Each step coincides with an energetic signature (0.3 kBT) that is conserved from bacteria to humans. Triplet recognition is strictly dependent on correct Watson-Crick pairing. Rad51, RecA, and Dmc1 can all step over mismatches, but only Dmc1 can stabilize mismatched triplets. This finding provides insight into why eukaryotes have evolved a meiosis-specific recombinase. We propose that canonical Watson-Crick base triplets serve as the fundamental unit of pairing interactions during DNA recombination.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4580133/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4580133/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lee, Ja Yil -- Terakawa, Tsuyoshi -- Qi, Zhi -- Steinfeld, Justin B -- Redding, Sy -- Kwon, YoungHo -- Gaines, William A -- Zhao, Weixing -- Sung, Patrick -- Greene, Eric C -- CA146940/CA/NCI NIH HHS/ -- GM074739/GM/NIGMS NIH HHS/ -- R01 CA146940/CA/NCI NIH HHS/ -- R01 ES015252/ES/NIEHS NIH HHS/ -- R01 GM074739/GM/NIGMS NIH HHS/ -- R01ES015252/ES/NIEHS NIH HHS/ -- T32 GM007367/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- New York, N.Y. -- Science. 2015 Aug 28;349(6251):977-81. doi: 10.1126/science.aab2666.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA. ; Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA. Department of Biophysics, Kyoto University, Sakyo, Kyoto, Japan. ; Department of Chemistry, Columbia University, New York, NY, USA. ; Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT, USA. ; Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA. Howard Hughes Medical Institute, Columbia University, New York, NY, USA. ecg2108@cumc.columbia.edu.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26315438" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Sequence ; Base Pairing ; Base Sequence ; Cell Cycle Proteins/chemistry/metabolism ; DNA/*chemistry/*metabolism ; DNA, Single-Stranded/metabolism ; DNA-Binding Proteins/chemistry/metabolism ; Escherichia coli Proteins/chemistry/metabolism ; Evolution, Molecular ; *Homologous Recombination ; Humans ; Meiosis ; Molecular Dynamics Simulation ; Molecular Sequence Data ; Rad51 Recombinase/chemistry/*metabolism ; Rec A Recombinases/chemistry/*metabolism ; Recombinases/chemistry/*metabolism ; Saccharomyces cerevisiae Proteins/chemistry/*metabolism ; Thermodynamics
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 7
    facet.materialart.
    Unknown
    Spontaneous Imbibition of Brine and Oil in Gas Shales: Effect of Water Adsorption and Resulting Microfractures (2013)
    American Chemical Society (ACS)
    Details
    Publication Date: 2013-05-30
    Description: Energy & Fuels DOI: 10.1021/ef4002814
    Print ISSN: 0887-0624
    Electronic ISSN: 1520-5029
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering , Process Engineering, Biotechnology, Nutrition Technology
    Published by American Chemical Society (ACS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 8
    facet.materialart.
    Unknown
    Research of Hybrid Three-phase equilibrium Technology (2016)
    Institute of Physics (IOP)
    Details
    Publication Date: 2016-09-27
    Description: This paper puts forward a kind of managerial method based on the combination of PPF (passive power filter) and APF (active power filter) for the problem of three-phase current balance in three-phase four-wire system. This method uses two special reactors to filter zero- sequence current and uses APF to filter negative-sequence fundamental current, positive- sequence and negative-sequence harmonic current. It is more effective, reliable and economic. This paper proves feasibility of the method by the simulation results.
    Print ISSN: 1755-1307
    Electronic ISSN: 1755-1315
    Topics: Geography , Geosciences , Physics
    Published by Institute of Physics (IOP)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 9
    facet.materialart.
    Unknown
    RNA editing of SLC22A3 drives early tumor invasion and metastasis in familial esophageal cancer [Medical Sciences] (2017)
    National Academy of Sciences
    Details
    Publication Date: 2017-06-07
    Description: Like many complex human diseases, esophageal squamous cell carcinoma (ESCC) is known to cluster in families. Familial ESCC cases often show early onset and worse prognosis than the sporadic cases. However, the molecular genetic basis underlying the development of familial ESCC is mostly unknown. We reported that SLC22A3 is significantly...
    Print ISSN: 0027-8424
    Electronic ISSN: 1091-6490
    Topics: Biology , Medicine , Natural Sciences in General
    Published by National Academy of Sciences
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 10
    facet.materialart.
    Unknown
    The optimization of fermentation conditions for producing cellulase of Bacillus amyloliquefaciens and its application to goose feed (2017)
    Royal Society
    Details
    Publication Date: 2017-10-26
    Description: The proper culture conditions for producing cellulase of Bacillus amyloliquefaciens S1, isolated from the cecum of goose was optimized by single-factor experiment combined with orthogonal test. The properties of the cellulase were investigated by DNS method. The appropriate doses of B. amyloliquefaciens S1 were obtained by adding them to goose feed. It indicated that the suitable culture conditions of producing cellulase were the culture temperature of 37°C, the initial pH of 7.0, the incubation time of 72 h and the loaded liquid volume of 75 ml per 250 ml. The effects of each factor on producing cellulase by B. amyloliquefaciens S1 were as follows: initial pH 〉 incubation time = culture temperature 〉 loaded liquid volume. The optimum reaction temperature and pH were 50°C and 7.0, respectively. This enzyme is a kind of neutral cellulase that possesses resistance to heat and acidity. It showed high activity to absorbent cotton, soya bean meal and filter paper. By adding different doses of B. amyloliquefaciens S1 to the goose feed, it was found that the egg production, average egg weight, fertilization rate and the hatching rate were promoted both in experiment 1 (1.5 g kg –1 ) and experiment 2 (3 g kg –1 ). Also the difference of egg production, fertilization rate and hatching rate between experiment 1 and control group was obvious ( p 〈 0.05), and the average egg weight was significantly increased in experiment 2 ( p 〈 0.05).
    Keywords: biochemistry
    Electronic ISSN: 2054-5703
    Topics: Natural Sciences in General
    Published by Royal Society
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...