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Structure of the 4-hydroxy-tetrahydrodipicolinate synthase from the thermoacidophilic methanotroph Methylacidiphilum fumariolicum SolV and the phylogeny of the aminotransferase pathway

The enzyme 4-hydroxy-tetrahydrodipicolinate synthase (DapA) is involved in the production of lysine and precursor molecules for peptidoglycan synthesis. In a multistep reaction, DapA converts pyruvate and l-aspartate-4-semialdehyde to 4-hydroxy-2,3,4,5-tetrahydrodipicolinic acid. In many organisms, lysine binds allosterically to DapA, causing negative feedback, thus making the enzyme an important regulatory component of the pathway. Here, the 2.1 Å resolution crystal structure of DapA from the thermoacidophilic methanotroph Methylacidiphilum fumariolicum SolV is reported. The enzyme crystallized as a contaminant of a protein preparation from native biomass. Genome analysis reveals that M. fumariolicum SolV utilizes the recently discovered aminotransferase pathway for lysine biosynthesis. Phylogenetic analyses of the genes involved in this pathway shed new light on the distribution of this pathway across the three domains of life.




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Tris­(4,4'-di-tert-butyl-2,2'-bi­pyridine)(trans-4-tert-butyl­cyclo­hexa­nolato)­deca-μ-oxido-hepta­oxido­hepta­vanadium aceto­nitrile monosolvate including another unknown solvent mol­ecule

The title hepta­nuclear alkoxido(oxido)vanadium(V) oxide cluster complex, [V7(C10H19O)O17(C18H24N2)3]·CH3CN, was obtained by the reaction of [V8O20(C18H24N2)4] with 4-tert-butyl­cyclo­hexa­nol (mixture of cis and trans) in a mixed CHCl3/CH3CN solvent. The complex has a V7O18N6 core with approximately Cs symmetry, which is composed of two VO4 tetra­hedra, two VO6 octa­hedra and three VO4N2 octa­hedra. In the crystal, these complexes are linked together by weak inter­molecular C—H⋯O hydrogen bonds between the 4,4'-di-tert-butyl-2,2'-bi­pyridine ligand and the V7O18N6 core, forming a one-dimensional network along the c-axis direction. Besides the complex, the asymmetric unit contains one CH3CN solvent mol­ecule. The contribution of other disordered solvent mol­ecules to the scattering was removed using the SQUEEZE option in PLATON [Spek (2015). Acta Cryst. C71, 9–18]. The unknown solvent mol­ecules are not considered in the chemical formula and other crystal data.




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Structure refinement of (NH4)3Al2(PO4)3 prepared by ionothermal synthesis in phospho­nium based ionic liquids – a redetermination

After crystallization during ionothermal syntheses in phospho­nium-containing ionic liquids, the structure of (NH4)3Al2(PO4)3 [tri­ammonium dialuminum tris­(phosphate)] was refined on the basis of powder X-ray diffraction data from a synchrotron source. (NH4)3Al2(PO4)3 is a member of the structural family with formula A3Al2(PO4)3, where A is a group 1 element, and of which the NH4, K, and Rb forms were previously known. The NH4 form is isostructural with the K form, and was previously solved from single-crystal X-ray data when the material (SIZ-2) crystallized from a choline-containing eutectic mixture [Cooper et al. (2004). Nature, 430, 1012–1017]. Our independent refinement incorporates NH4 groups and shows that these NH4 groups are hydrogen bonded to framework O atoms present in rings containing 12 T sites in a channel along the c-axis direction. We describe structural details of (NH4)3Al2(PO4)3 and discuss differences with respect to isostructural forms.




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Radiation damage in small-molecule crystallography: fact not fiction

Traditionally small-molecule crystallographers have not usually observed or recognized significant radiation damage to their samples during diffraction experiments. However, the increased flux densities provided by third-generation synchrotrons have resulted in increasing numbers of observations of this phenomenon. The diversity of types of small-molecule systems means it is not yet possible to propose a general mechanism for their radiation-induced sample decay, however characterization of the effects will permit attempts to understand and mitigate it. Here, systematic experiments are reported on the effects that sample temperature and beam attenuation have on radiation damage progression, allowing qualitative and quantitative assessment of their impact on crystals of a small-molecule test sample. To allow inter-comparison of different measurements, radiation-damage metrics (diffraction-intensity decline, resolution fall-off, scaling B-factor increase) are plotted against the absorbed dose. For ease-of-dose calculations, the software developed for protein crystallography, RADDOSE-3D, has been modified for use in small-molecule crystallography. It is intended that these initial experiments will assist in establishing protocols for small-molecule crystallographers to optimize the diffraction signal from their samples prior to the onset of the deleterious effects of radiation damage.




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Structure of the 4-hydroxy-tetrahydrodipicolinate synthase from the thermoacidophilic methanotroph Methylacidiphilum fumariolicum SolV and the phylogeny of the aminotransferase pathway

Insights were obtained into the structure of the 4-hydroxy-tetrahydrodipicolinate synthase from the thermoacidophilic methanotroph Methylacidiphilum fumariolicum SolV and the phylogeny of the aminotransferase pathway for the biosynthesis of lysine.




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Crystal structure of an oxidized mutant of human mitochondrial branched-chain aminotransferase

This study presents the crystal structure of a thiol variant of the human mitochondrial branched-chain aminotransferase protein. Human branched-chain aminotransferase (hBCAT) catalyzes the transamination of the branched-chain amino acids leucine, valine and isoleucine and α-ketoglutarate to their respective α-keto acids and glutamate. hBCAT activity is regulated by a CXXC center located approximately 10 Å from the active site. This redox-active center facilitates recycling between the reduced and oxidized states, representing hBCAT in its active and inactive forms, respectively. Site-directed mutagenesis of the redox sensor (Cys315) results in a significant loss of activity, with no loss of activity reported on the mutation of the resolving cysteine (Cys318), which allows the reversible formation of a disulfide bond between Cys315 and Cys318. The crystal structure of the oxidized form of the C318A variant was used to better understand the contributions of the individual cysteines and their oxidation states. The structure reveals the modified CXXC center in a conformation similar to that in the oxidized wild type, supporting the notion that its regulatory mechanism depends on switching the Cys315 side chain between active and inactive conformations. Moreover, the structure reveals conformational differences in the N-terminal and inter-domain region that may correlate with the inactivated state of the CXXC center.




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National Zoo’s giant panda Mei Xiang is not pregnant

Based on current hormone analyses, and not having seen a fetus during the ultrasound exams, Zoo researchers have determined that Mei Xiang experienced a pseudopregnancy.

The post National Zoo’s giant panda Mei Xiang is not pregnant appeared first on Smithsonian Insider.




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Don’t pick a fight with a eunuch spider. It has nothing to lose

In a recent study of the mating behavior of these Asian spiders, researchers found that 87.5 percent of males had both palps amputated during copulation.

The post Don’t pick a fight with a eunuch spider. It has nothing to lose appeared first on Smithsonian Insider.




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What makes rainforests unique? History, not ecology.

History and geology, not current ecology, are likely what has made tropical forests so variable from site to site.

The post What makes rainforests unique? History, not ecology. appeared first on Smithsonian Insider.




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Fancy footwork and non-stick leg coating helps spiders not stick to their own webs

Researchers at the Smithsonian Tropical Research Institute and University of Costa Rica studying why spiders do not stick to their own sticky webs have discovered that a spider's legs are protected by a covering of branching hairs and by a non-stick chemical coating. Their results are published online in the journal, Naturwissenschaften.

The post Fancy footwork and non-stick leg coating helps spiders not stick to their own webs appeared first on Smithsonian Insider.




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Not on a plane, but how did blind snakes ever get to the Pacific’s Caroline Islands?

Two new species of blind snakes found living on small, low-lying atolls in the Caroline Islands, are an unexpected discovery that is quite difficult to explain,

The post Not on a plane, but how did blind snakes ever get to the Pacific’s Caroline Islands? appeared first on Smithsonian Insider.




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Scientists find that rain may not always be a welcome thing to waterbirds

Their research revealed that the types of waterbirds that inhabit urban estuaries are influenced not only by urban development, but also by a far more natural process―rain.

The post Scientists find that rain may not always be a welcome thing to waterbirds appeared first on Smithsonian Insider.




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Scientists discover long-beaked echidna may not be a thing of the past in Australia

The western long-beaked echidna, one of the world's five egg-laying species of mammal, became extinct in Australia thousands of years ago…or did it?

The post Scientists discover long-beaked echidna may not be a thing of the past in Australia appeared first on Smithsonian Insider.




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Note to St. Patrick: Pls. keep the snakes

According to legend St. Patrick (circa 387–460 or 492 AD) banished all snakes from Ireland, chasing them into the sea after they attacked him during […]

The post Note to St. Patrick: Pls. keep the snakes appeared first on Smithsonian Insider.




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Interstellar exploration – five planets where humans may (or may not) be able to live someday

Unless you live under a lunar rock, you’ve probably heard about or seen director Christopher Nolan’s latest blockbuster “Interstellar.” Starring Anne Hathaway and Matthew McConaughey, […]

The post Interstellar exploration – five planets where humans may (or may not) be able to live someday appeared first on Smithsonian Insider.




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Cownose Rays Aquitted: Not Guilty of Decimating Chesapeake Oysters

Ten years ago, cownose rays in the Atlantic got a bad rap when this species (Rhinoptera bonasus) was accused of excessively eating up scallops in […]

The post Cownose Rays Aquitted: Not Guilty of Decimating Chesapeake Oysters appeared first on Smithsonian Insider.





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Planet 9: A world that should not exist

Earlier this year scientists presented evidence for Planet Nine, a Neptune-mass planet in an elliptical orbit 10 times farther from our Sun than Pluto. Since […]

The post Planet 9: A world that should not exist appeared first on Smithsonian Insider.





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Farthest Milky Way stars might be ripped from another galaxy

The 11 farthest known stars in our galaxy are located about 300,000 light-years from Earth, well outside the Milky Way’s spiral disk. New research by […]

The post Farthest Milky Way stars might be ripped from another galaxy appeared first on Smithsonian Insider.



  • Science & Nature
  • Space
  • Center for Astrophysics | Harvard & Smithsonian
  • Milky Way
  • Smithsonian Astrophysical Observatory

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Gold nanotechnology and lasers used to successfully freeze fish embryos

For more than 60 years, researchers have tried to successfully cryopreserve (or freeze) the embryo of zebrafish, a species that is an important medical model […]

The post Gold nanotechnology and lasers used to successfully freeze fish embryos appeared first on Smithsonian Insider.




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Poachers are killing endangered Asian elephants for their skin and meat, not their tusks

Poaching wasn’t the largest conservation concern for Asian elephants, an endangered species, until satellite tracking stunned researchers. Scientists at the Smithsonian Conservation Biology Institute (SCBI) […]

The post Poachers are killing endangered Asian elephants for their skin and meat, not their tusks appeared first on Smithsonian Insider.



  • Animals
  • History & Culture
  • Science & Nature
  • Smithsonian Conservation Biology Institute

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Protecting Puerto Rico’s heritage from another disaster

When a natural disaster strikes, it devastates lives and homes, and can even destroy a culture’s identity and history. After a disaster, humanitarian response is […]

The post Protecting Puerto Rico’s heritage from another disaster appeared first on Smithsonian Insider.



  • Art
  • History & Culture
  • Science & Nature

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Audio not working at all on ThinkPad R30




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Win95b not detecting pcmcia network card *pulling my hair out*




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Automated 3D light-sheet screening with high spatiotemporal resolution reveals mitotic phenotypes [TOOLS AND RESOURCES]

Björn Eismann, Teresa G. Krieger, Jürgen Beneke, Ruben Bulkescher, Lukas Adam, Holger Erfle, Carl Herrmann, Roland Eils, and Christian Conrad

3D cell cultures enable the in vitro study of dynamic biological processes such as the cell cycle, but their use in high-throughput screens remains impractical with conventional fluorescent microscopy. Here, we present a screening workflow for the automated evaluation of mitotic phenotypes in 3D cell cultures by light-sheet microscopy. After sample preparation by a liquid handling robot, cell spheroids are imaged for 24 hours in toto with a dual-view inverted selective plane illumination microscope (diSPIM) with a much improved signal-to-noise ratio, higher imaging speed, isotropic resolution and reduced light exposure compared to a spinning disc confocal microscope. A dedicated high-content image processing pipeline implements convolutional neural network based phenotype classification. We illustrate the potential of our approach by siRNA knock-down and epigenetic modification of 28 mitotic target genes for assessing their phenotypic role in mitosis. By rendering light-sheet microscopy operational for high-throughput screening applications, this workflow enables target gene characterization or drug candidate evaluation in tissue-like 3D cell culture models.




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Maturation and phenotype of pathophysiological neuronal excitability of human cells in tau-related dementia [RESEARCH ARTICLE]

Olga Kopach, Noemi Esteras, Selina Wray, Dmitri A. Rusakov, and Andrey Y. Abramov

Frontotemporal dementia and parkinsonism (FTDP-17) caused by the 10+16 splice-site mutation in the MAPT provides an established platform to model tau-related dementia in vitro. Human iPSC-derived neurons have been shown to recapitulate the neurodevelopmental profile of tau pathology during in vitro corticogenesis as in the adult human brain. However, the neurophysiological phenotype of these cells has remained unknown, leaving unanswered questions over the functional relevance and the gnostic power of this disease model. Here we used electrophysiology to explore the membrane properties and intrinsic excitability of the generated neurons to find that human cells mature by ~150 days of neurogenesis to become compatible with matured cortical neurons. In earlier FTDP-17, neurons, however, exhibited a depolarized resting membrane potential associated with increased resistance and reduced voltage-gated Na+- and K+-channel-mediated conductance. The Nav1.6 protein was reduced in FTDP-17. These led to a reduced cell capability of induced firing and changed action potential waveform in FTDP-17. The revealed neuropathology may thus contribute to the clinicopathological profile of the disease. This sheds new light on the significance of human models of dementia in vitro.




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Another Earth? Kepler astronomers pinpoint likeliest candidates

Looking for another Earth? An international team of researchers has pinpointed which of the more than 4,000 exoplanets discovered by NASA’s Kepler mission are most […]

The post Another Earth? Kepler astronomers pinpoint likeliest candidates appeared first on Smithsonian Insider.





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Changing The Mail Notification Sound In Opera




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Cannot download AdwCleaner to Windows phone




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My Windows phone not working fine when connected to Wi-Fi!




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my windows phone is not copying




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Nokia Lumia not synching




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MP3 Player That Does Not Make Unwanted Noise




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Remove the Press Allow to watch the video Notification Page

If you see a web site that states "Press <> to watch the video" and then prompts you to allow browser notifications, do not click on the allow button. These sites are just trying to trick you into subscribing to their browser notifications so that they can send notification spam directly to your desktop.

This article was published first at Remove the Press Allow to watch the video Notification Page




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Vista is not booting anymore / blue screen of death




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New project will improve access to thousands of scientific field books, journals and notes in Smithsonian collections

In 1909, naturalist Dr. Edgar A. Mearns joined Theodore Roosevelt and scientists from the Smithsonian and New York’s American Museum of Natural History on an […]

The post New project will improve access to thousands of scientific field books, journals and notes in Smithsonian collections appeared first on Smithsonian Insider.




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Computer frequently stuck with apps in Not Responding mode for 2-30 seconds




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Computer frequently stuck with apps in Not Responding mode for 2-30 seconds




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Google Chrome malware ads will not go away




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MATLAB - When opening a text file with UTF-16 or UTF-32 encoding using the Import Tool, a warning message is shown, and if you proceed, the data may not be imported correctly.

If you try to open a text file with UTF-16 or UTF-32 encoding, the Import Tool displays a warning message stating that the encoding is not supported.  If you continue to load the file anyways, it is opened with UTF-8 encoding, and the file may not be displayed or imported as expected.This bug exists in the following release(s):
R2020a

This bug has a workaround

Interested in Upgrading?




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Cannot open Windows Firewall




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My Chrome Browser is not allowing me to access YouTube????




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how to merge data from 2 COLORNOTE files




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This google account not associated with device, blah, blah, blah...