This simulated image shows the Giant Magellan Telescope in operation in Chile while deploying lasers for its adaptive-optics system. The GMT is scheduled to begin […]

The post Giant Magellan Telescope appeared first on Smithsonian Insider.

Rope, golf balls, sweat pants, bottles and aluminum cans are a few of the discarded items biologist Matt Klope says he has found inside the […]

The post Gray whale specimen an important addition to Natural History Museum collections appeared first on Smithsonian Insider.

There is little doubt that human activity is affecting planet Earth, but just how much? And is it all negative? Rick Potts is the director […]

The post Smithsonian anthropologist Rick Potts answers questions about the Anthropocene appeared first on Smithsonian Insider.

Based on a treasure trove of recent discoveries, astronomers now know that planets are remarkably plentiful in our galaxy and may be common throughout the […]

The post Dust trap around distant star may unlock mystery as to how planets form appeared first on Smithsonian Insider.

Scientists at the Smithsonian Conservation Biology Institute’s Center for Conservation and Evolutionary Genetics have confirmed that the giant panda cub born at the National Zoo […]

The post National Zoo’s giant panda cub is a girl! appeared first on Smithsonian Insider.

Roses, carnations and lilies are today among the most popular flowers people use to express sympathy and condolence. The simple act of sending flowers to […]

The post Funeral flowers in the Stone Age: Q&A with Smithsonian anthropologist Reuven Yeshurun appeared first on Smithsonian Insider.

W49A might be one of the best-kept secrets in our galaxy. This star-forming region shines 100 times brighter than the Orion nebula, but is so […]

The post SMA reveals giant star cluster in the making appeared first on Smithsonian Insider.

Scientists at the Smithsonian’s National Museum of Natural History have discovered a new genus and species of attine ants that reveals key clues in the […]

The post Smithsonian scientists discover new ghost ant genus and species appeared first on Smithsonian Insider.

Ants dominate the earth’s ecosystems and many are voracious predators that use their mandibles and sheer numbers to pin down and tear apart most other […]

The post Carabidae in the colony, seven new beetles that bunk with ants: Q&A with Terry Erwin appeared first on Smithsonian Insider.

It is related to one of the world’s most destructive invasive species, and possibly the slimiest. Thirty-five pounds of live giant West African snails (Archachatina […]

The post Slimy invaders, giant snails: Q&A with mollusk expert Ellen Strong appeared first on Smithsonian Insider.

A newly-discovered species of ant supports a controversial theory of species formation. The ant, known to live only under a single eucalyptus tree on the […]

The post Deadbeat ant species branched off as parasite inside its own colony appeared first on Smithsonian Insider.

Archived feed of this symposium » The world is changing at a rapid pace. Scientists have documented significant changes during the past century in climate, […]

The post Smithsonian Symposium: The Anthropocene appeared first on Smithsonian Insider.

What do you want to be when you grow up? Would you want to explore the world searching for long lost creatures of our past? […]

The post Five amazing fossil finds that will make you want to be a fossil hunter appeared first on Smithsonian Insider.

Millions of people across the United States will sit down Nov. 27 to a traditional Thanksgiving meal, including turkey, potatoes, squash, corn and cranberries. These […]

The post Where did your favorite Thanksgiving Day food originate? Anthropology has the answer appeared first on Smithsonian Insider.

A new study of microorganisms living on the skin and in the intestines of North America vultures (black and turkey vultures) has turned up a […]

The post Vultures remarkably tolerant to deadly bacteria, study reveals appeared first on Smithsonian Insider.

Cassiopeia A, or Cas A for short, is one of the most well studied supernova remnants in our galaxy. But it still holds major surprises.  […]

The post 3-D Map of Supernova Remnant Reveals Frothy Interior appeared first on Smithsonian Insider.

For the first time, astronomers have detected the presence of complex organic molecules, the building blocks of life, in a protoplanetary disk surrounding a young […]

The post Complex Organic Molecules Discovered in Infant Star System appeared first on Smithsonian Insider.

How soon after the Big Bang could water have existed? Not right away, because water molecules contain oxygen and oxygen had to be formed in […]

The post Water may Have Been Abundant in First Billion Years after big bang appeared first on Smithsonian Insider.

Two rovers are active right now on the surface of Mars: Opportunity, which landed in January 2004, and Curiosity, which started exploration in August 2012. […]

The post Sol Man: John Grant is on a road trip across Mars appeared first on Smithsonian Insider.

In many ways stars are like living beings. They’re born; they live; they die. And they even have a heartbeat. Using a novel technique, astronomers […]

The post DISCOVERY MEASURES “HEARTBEATS” OF A DISTANT GALAXY’S STARS appeared first on Smithsonian Insider.

A new analysis of the fossil record by scientists at the Smithsonian’s National Museum of Natural History has revealed that the structure of plant and […]

The post Smithsonian Scientists Trace Anthropocene Roots to Early Human Activity appeared first on Smithsonian Insider.

She was a stunning brown queen; drowned some 46 million years ago in a shallow lake in Montana. Her remains, recently recovered along the Flathead […]

The post New Montana ant species emerge from 46-million-year-old rock appeared first on Smithsonian Insider.

If you were an average person in the 18th and early 19th centuries, chances are your wardrobe was 50 shades of beige, with maybe a […]

The post A Purple Accident and Its Vibrant Impact on the Modern World appeared first on Smithsonian Insider.

Astronomers announced today that they have found the organic molecule methyl alcohol, or methanol, in the TW Hydrae protoplanetary disk. This is the first such […]

The post Methanol reveals comets forming in distant solar system appeared first on Smithsonian Insider.

Thirty years after the scimitar-horned oyrx were driven to extinction, the desert antelope will return to the last-known place it existed: Chad’s Sahelian grasslands. The […]

The post Extinct-in-the-Wild Antelope Return to the Grasslands of Chad appeared first on Smithsonian Insider.

Washington, D.C. is a city of symbols. The rites, rituals, and places that define Washington capture the aspirations of our nation and its citizens. Just […]

The post Trusted Sources: Why Museums and Libraries Are More Relevant Than Ever appeared first on Smithsonian Insider.

The blue whale, which uses baleen to filter its prey from ocean water and can reach lengths of over 100 feet, is the largest vertebrate […]

The post Only recently did whales become giant appeared first on Smithsonian Insider.

In everyday life, ultraviolet, or UV, light earns a bad reputation for being responsible for sunburns and other harmful effects on humans. However, research suggests […]

The post In search for life, ultraviolet light may be ultra important appeared first on Smithsonian Insider.

In conflicts between predators and prey, speed is a decided advantage, and evolution has given the trap-jaw ant a distinct advantage with spring-loaded jaws that […]

The post Locked and loaded: unique trigger design fires this ant’s snapping jaws appeared first on Smithsonian Insider.

The Giant Magellan Telescope Organization (GMTO) today announced that it has initiated the casting of the fifth of seven mirrors that will form the heart of […]

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With a non-stop babble of hums, grunts and shrill squeals as they argue over fish and defend their territories, the Amazon’s giant otters are one […]

The post With voices joined in chorus, giant otter families create a distinct sound signature appeared first on Smithsonian Insider.

The center of our Galaxy has been intensely studied for many years, but it still harbors surprises for scientists. A snake-like structure lurking near our […]

The post Cosmic filament probes our galaxy’s giant black hole appeared first on Smithsonian Insider.

In 1854, a curious-looking spider was found preserved in 50 million-year-old amber. With an elongated neck-like structure and long mouthparts that protruded from the “head” […]

The post These newly discovered pelican spiders will make you want to visit Madagascar appeared first on Smithsonian Insider.

There are currently more than 3,500 confirmed known exoplanets thanks to the remarkable sensitivity of the Kepler spacecraft and to technological advances in space and […]

The post Astronomers detect comets transiting distant stars appeared first on Smithsonian Insider.

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.

The biological processes related to protein homeostasis in Mycobacterium tuberculosis, the etiologic agent of tuberculosis, have recently been established as critical pathways for therapeutic intervention. Proteins of particular interest are ClpC1 and the ClpC1–ClpP1–ClpP2 proteasome complex. The structure of the potent antituberculosis macrocyclic depsipeptide ecumicin complexed with the N-terminal domain of ClpC1 (ClpC1-NTD) is presented here. Crystals of the ClpC1-NTD–ecumicin complex were monoclinic (unit-cell parameters a = 80.0, b = 130.0, c = 112.0 Å, β = 90.07°; space group P21; 12 complexes per asymmetric unit) and diffracted to 2.5 Å resolution. The structure was solved by molecular replacement using the self-rotation function to resolve space-group ambiguities. The new structure of the ecumicin complex showed a unique 1:2 (target:ligand) stoichiometry exploiting the intramolecular dyad in the α-helical fold of the target N-terminal domain. The structure of the ecumicin complex unveiled extensive interactions in the uniquely extended N-terminus, a critical binding site for the known cyclopeptide complexes. This structure, in comparison with the previously reported rufomycin I complex, revealed unique features that could be relevant for understanding the mechanism of action of these potential antituberculosis drug leads. Comparison of the ecumicin complex and the ClpC1-NTD-L92S/L96P double-mutant structure with the available structures of rufomycin I and cyclomarin A complexes revealed a range of conformational changes available to this small N-terminal helical domain and the minor helical alterations involved in the antibiotic-resistance mechanism. The different modes of binding and structural alterations could be related to distinct modes of action.

Death-associated protein kinase 1 (DAPK1) is a serine/threonine protein kinase that regulates apoptosis and autophagy. DAPK1 is considered to be a therapeutic target for amyloid-β deposition, endometrial adenocarcinomas and acute ischemic stroke. Here, the potent inhibitory activity of the natural anthraquinone purpurin against DAPK1 phosphorylation is shown. Thermodynamic analysis revealed that while the binding affinity of purpurin is similar to that of CPR005231, which is a DAPK1 inhibitor with an imidazopyridazine moiety, the binding of purpurin was more enthalpically favorable. In addition, the inhibition potencies were correlated with the enthalpic changes but not with the binding affinities. Crystallographic analysis of the DAPK1–purpurin complex revealed that the formation of a hydrogen-bond network is likely to contribute to the favorable enthalpic changes and that stabilization of the glycine-rich loop may cause less favorable entropic changes. The present findings indicate that purpurin may be a good lead compound for the discovery of inhibitors of DAPK1, and the observation of enthalpic changes could provide important clues for drug development.

Mycoplasma hyopneumoniae is a prokaryotic pathogen that colonizes the respiratory ciliated epithelial cells in swine. Infected animals suffer respiratory lesions, causing major economic losses in the porcine industry. Characterization of the immunodominant membrane-associated proteins from M. hyopneumoniae may be instrumental in the development of new therapeutic approaches. Here, the crystal structure of P46, one of the main surface-antigen proteins, from M. hyopneumoniae is presented and shows N- and C-terminal α/β domains connected by a hinge. The structures solved in this work include a ligand-free open form of P46 (3.1 Å resolution) and two ligand-bound structures of P46 with maltose (2.5 Å resolution) and xylose (3.5 Å resolution) in open and closed conformations, respectively. The ligand-binding site is buried in the cleft between the domains at the hinge region. The two domains of P46 can rotate with respect to each other, giving open or closed alternative conformations. In agreement with this structural information, sequence analyses show similarities to substrate-binding members of the ABC transporter superfamily, with P46 facing the extracellular side as a functional subunit. In the structure with xylose, P46 was also bound to a high-affinity (Kd = 29 nM) Fab fragment from a monoclonal antibody, allowing the characterization of a structural epitope in P46 that exclusively involves residues from the C-terminal domain. The Fab structure in the complex with P46 shows only small conformational rearrangements in the six complementarity-determining regions (CDRs) with respect to the unbound Fab (the structure of which is also determined in this work at 1.95 Å resolution). The structural information that is now available should contribute to a better understanding of sugar nutrient intake by M. hyopneumoniae. This information will also allow the design of protocols and strategies for the generation of new vaccines against this important swine pathogen.

Leucocyte common antigen-related protein (LAR) is a post-synaptic type I transmembrane receptor protein that is important for neuronal functionality and is genetically coupled to neuronal disorders such as attention deficit hyperactivity disorder (ADHD). To understand the molecular function of LAR, structural and biochemical studies of protein fragments derived from the ectodomain of human LAR have been performed. The crystal structure of a fragment encompassing the first four FNIII domains (LARFN1–4) showed a characteristic L shape. SAXS data suggested limited flexibility within LARFN1–4, while rigid-body refinement of the SAXS data using the X-ray-derived atomic model showed a smaller angle between the domains defining the L shape compared with the crystal structure. The capabilities of the individual LAR fragments to interact with heparin was examined using microscale thermophoresis and heparin-affinity chromatography. The results showed that the three N-terminal immunoglobulin domains (LARIg1–3) and the four C-terminal FNIII domains (LARFN5–8) both bound heparin, while LARFN1–4 did not. The low-molecular-weight heparin drug Innohep induced a shift in hydrodynamic volume as assessed by size-exclusion chromatography of LARIg1–3 and LARFN5–8, while the chemically defined pentameric heparin drug Arixtra did not. Together, the presented results suggest the presence of an additional heparin-binding site in human LAR.

Supplying archaeological and oceanographic evidence, this book persuasively links Clovis technology with the culture of the Solutrean people who occupied France and Spain more than 20,000 years ago.

The post New Book: “Across Atlantic Ice : The Origin of America’s Clovis Culture” appeared first on Smithsonian Insider.

Some of the earliest humans to inhabit America came from Europe according to a new book "Across Atlantic Ice: The Origin of America's Clovis Culture."

The post New book reveals Ice Age mariners from Europe were America’s first inhabitants appeared first on Smithsonian Insider.

Between the world wars of the early Twentieth Century, an age of adventure travel and cultural exploration flourished when newly developed transport and recording technologies–particularly […]

The post New Book: “Recreating First Contact: Expeditions, Anthropology, and Popular Culture” appeared first on Smithsonian Insider.

Westley Heydeck, Brian A. Bayless, Alexander J. Stemm-Wolf, Eileen T. O'Toole, Amy S. Fabritius, Courtney Ozzello, Marina Nguyen, and Mark Winey

Basal bodies (BBs) are microtubule-based organelles that template and stabilize cilia at the cell surface. Centrins ubiquitously associate with BBs and function in BB assembly, maturation, and stability. Human POC5 (hPOC5) is a highly conserved centrin-binding protein that binds centrins through Sfi1p-like repeats and is required for building full-length, mature centrioles. Here, we use the BB-rich cytoskeleton of Tetrahymena thermophila to characterize Poc5 BB functions. Tetrahymena Poc5 (TtPoc5) uniquely incorporates into assembling BBs and is then removed from mature BBs prior to ciliogenesis. Complete genomic knockout of TtPOC5 leads to a significantly increased production of BBs yet a markedly reduced ciliary density, both of which are rescued by reintroduction of TtPoc5. A second Tetrahymena POC5-like gene, SFR1, is similarly implicated in modulating BB production. When TtPOC5 and SFR1 are co-deleted, cell viability is compromised, and levels of BB overproduction are exacerbated. Overproduced BBs display defective transition zone formation and a diminished capacity for ciliogenesis. This study uncovers a requirement for Poc5 in building mature BBs, providing a possible functional link between hPOC5 mutations and impaired cilia.

The pendant took Grand Prize in the National Saul Bell Design Competition in 2008 and features a beautiful 3.76-ct pink tourmaline from Nigeria.

The post Pink tourmaline “Nautilus” pendant enters National Gem Collection appeared first on Smithsonian Insider.

NASA, the National Science Foundation and the Smithsonian recently renewed their agreement to search for, collect and curate Antarctic meteorites in a partnership known as […]

The post NASA, Smithsonian renew hunt for Antarctic meteorites appeared first on Smithsonian Insider.

Antarctica is home to fewer insect species than anywhere else on earth. But it wasn’t always that way. A geologist digging in bluffs on Antarctica’s […]

The post One cold bug: Fossil beetle discovered in Antarctica appeared first on Smithsonian Insider.

Appendices B4 and B5 of Cayron [Acta Cryst. (2019), A75, 411–437] contain equations involving the point group and the metric tensor in which the equality symbol should be substituted by the inclusion symbol.