The crystal structure of malayaite, CaSnOSiO4, at T = 20 K has been refined, based on the presence of satellite reflections with a modulation vector of 0.26b*. The structural modulation is attributed to a soft optic phonon, dominated by motion of the Ca atoms.

The crystal structure of the nanocrystalline pigment mono­methyl-quinacridone was solved from X-ray powder data. The orientational disorder was investigated using Rietveld refinements, structure refinement to the pair-distribution function, and lattice-energy minimizations of various ordered structural models.

A single-chain, tailless Xenopus laevis H2A/H2B dimer construct (scH2BH2A) was engineered by directly fusing the C-terminus of H2B to the N-terminus of H2A without an artificial linker sequence. A high-resolution crystal structure of scH2BH2A shows that it adopts a nearly identical fold to that of nucleosomal H2A/H2B and may be useful for future structural studies of many H2A/H2B-interacting proteins.

The structure of the Pseudomonas aeruginosa T6SS PldB immunity protein PA5086 is reported at 1.9 Å resolution. Comparison of PA5086 with its homologs PA5087 and PA5088 showed great similarities in sequence and structure, but vast divergences in electrostatic potential surfaces.

Archaea are motile by the rotation of the archaellum. The archaellum switches between clockwise and counterclockwise rotation, and movement along a chemical gradient is possible by modulation of the switching frequency. This modulation involves the response regulator CheY and the archaellum adaptor protein CheF. In this study, two new crystal forms and protein structures of CheY are reported. In both crystal forms, CheY is arranged in a domain-swapped conformation. CheF, the protein bridging the chemotaxis signal transduction system and the motility apparatus, was recombinantly expressed, purified and subjected to X-ray data collection.

The crystallization of amidase, the ultimate enzyme in the Trp-dependent auxin-biosynthesis pathway, from Arabidopsis thaliana was attempted using protein samples with at least 95% purity. Cube-shaped crystals that were assumed to be amidase crystals that belonged to space group I4 (unit-cell parameters a = b = 128.6, c = 249.7 Å) were obtained and diffracted to 3.0 Å resolution. Molecular replacement using structures from the PDB containing the amidase signature fold as search models was unsuccessful in yielding a convincing solution. Using the Sequence-Independent Molecular replacement Based on Available Databases (SIMBAD) program, it was discovered that the structure corresponded to dihydrolipoamide succinyltransferase from Escherichia coli (PDB entry 1c4t), which is considered to be a common crystallization contaminant protein. The structure was refined to an Rwork of 23.0% and an Rfree of 27.2% at 3.0 Å resolution. The structure was compared with others of the same protein deposited in the PDB. This is the first report of the structure of dihydrolipo­amide succinyltransferase isolated without an expression tag and in this novel crystal form.

The membrane protein EsaA is a conserved component of the type VIIb secretion system. Limited proteolysis of purified EsaA from Staphylococcus aureus USA300 identified a stable 48 kDa fragment, which was mapped by fingerprint mass spectrometry to an uncharacterized extracellular segment of EsaA. Analysis by circular dichroism spectroscopy showed that this fragment folds into a single stable domain made of mostly α-helices with a melting point of 34.5°C. Size-exclusion chromatography combined with multi-angle light scattering indicated the formation of a dimer of the purified extracellular domain. Octahedral crystals were grown in 0.2 M ammonium citrate tribasic pH 7.0, 16% PEG 3350 using the hanging-drop vapor-diffusion method. Diffraction data were analyzed to 4.0 Å resolution, showing that the crystals belonged to the enantiomorphic tetragonal space groups P41212 or P43212, with unit-cell parameters a = 197.5, b = 197.5, c = 368.3 Å, α = β = γ = 90°.

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.

Describing his project of counting bears, bobcats and other predatory mammals along the Appalachian Trail, National Zoological Park wildlife ecologist William McShea looks to American literature for a comparison.

The post Appalachian Trail survey aims hidden cameras at large predators appeared first on Smithsonian Insider.

Each year thousands of vacationers enjoy the scenery along Virginia’s Skyline Drive, little knowing that for a few brief moments they are passing through the territory of an endangered […]

The post Study aims to give endangered Shenandoah salamander better odds at survival appeared first on Smithsonian Insider.

The Smithsonian Tropical Research Institute in Panama was recently given a collection of more than 25,000 different pollen grains and spores, each mounted on a microscope slide and labeled according to the plant that produced it. “The collection is worldwide in coverage with an emphasis on plants of the Americas,” explains collection donor Alan Graham, professor emeritus at Kent State University and curator at the Missouri Botanical Garden.

The post Research collection of pollen grains given to Smithsonian Tropical Research Institute appeared first on Smithsonian Insider.

Determining the locations of future highways and roads in countries with tropical rainforests will be the greatest single factor in influencing future forest loss, fragmentation and degradation. In broad terms, roads can be thought of as the enemies of rainforests. By spreading people out across the forest, roads inherently promote rapid and widespread deforestation.

The post Roads kill rainforests. Stop them now, say Smithsonian biologists appeared first on Smithsonian Insider.

The Smithsonian’s National Air and Space Museum has opened a new Public Observatory that contains a 16-inch, 3,000-pound Boller and Chivens telescope, on loan from the Smithsonian Astrophysical Observatory. Through this powerful telescope, museum visitors can now observe the sun (with a special filter), the moon and the brighter stars and planets, such as Venus, Jupiter and Saturn, during daylight hours. Funding for the project was provided by the National Science Foundation.

The post The Smithsonian’s National Air and Space Museum opens new Public Observatory on the Mall in Washington, D.C. appeared first on Smithsonian Insider.

White, who was a student at Columbian College from Accomack County, Va., died of pneumonia and complications from a mitral heart defect. When his coffin was unearthed, his identity was a deep mystery.

The post Remains of William Taylor White (1837-1852) donated to Smithsonian with his coffin and clothing appeared first on Smithsonian Insider.

Eleven bats remain in the National Zoo’s colony. The initial challenge the team faced was how to feed the animals. Virginia big-eared bats, which are a subspecies of the Townsend’s big-eared bat (Corynorhinuss townsendii), eat while flying.

The post Captive colony of Virginia big-eared bats providing valuable lessons in battle against deadly white-nose syndrome appeared first on Smithsonian Insider.

Recently, scientists at the Smithsonian Tropical Research Institute in Panama discovered that the brain region responsible for learning and memory is larger in the social queens than in the solitary queens of this species. Their study is the first comparison of the brain sizes of social and non-social individuals of the same species.

The post For sweat bees, being social builds a more developed brain appeared first on Smithsonian Insider.

When it comes to brains, is bigger better? Can the tiny brain of a newly hatched spiderling handle problems as adeptly as the brain of a larger adult spider?

The post Tiny, new brains prove just as adept as large, mature brains among tropical orb-web spiders appeared first on Smithsonian Insider.

Kiwis come to National Zoo. The Smithsonian’s National Zoo will be using a new kiwi pair donated by the New Zealand Embassy to establish a breeding science center. […]

The post New Zealand Embassy donates kiwi pair to National Zoo Breeding Science Center appeared first on Smithsonian Insider.

Unless action is taken now, coral reefs and many of the animals that depend on them may cease to exist within the next 40 years, causing the first global extinction of a worldwide ecosystem during current history.

The post Scientists establish first frozen repository of Hawaiian coral appeared first on Smithsonian Insider.

The Smithsonian’s National Zoo celebrated the completion of Phase I of Elephant Trails, an innovative and expanded home for Asian elephants, on Sept. 2. Phase […]

The post Elephant Trails exhibition opens at National Zoological Park appeared first on Smithsonian Insider.

Using the ancient magnetic field recorded in these rocks, a Smithsonian research group revealed Santa Marta’s 2,200-kilometer journey from northern Peru to its modern position on the Caribbean coast of Colombia during the past 170 million years.

The post Earth’s highest coastal mountain range moved 1,367 miles in 170 million years appeared first on Smithsonian Insider.

The Martian moons, Phobos and Deimos, may have been the result of a giant impact that sent rocks and debris into orbit around Mars, instead of asteroids that were captured by the planet’s gravity as previously thought.

The post Giant impact may explain origin of Martian moons Phobos and Deimos appeared first on Smithsonian Insider.

Water is a critical molecule for human life, and, because it is abundant in space, it also plays an important role in the life of […]

The post Astronomers appraise the amount of water in the Orion Nebula appeared first on Smithsonian Insider.

The words “box jelly” may bring to mind something sweet and tasty, but the banded box jelly of Bonaire is a highly venomous jellyfish with […]

The post “Ohboya!” It’s the Bonaire banded box jellyfish, a new species appeared first on Smithsonian Insider.

“Our results support the idea that environmental conditions on tropical non-breeding areas can influence the departure time for spring migration,” said Colin Studds, a postdoctoral fellow at the Smithsonian Conservation Biology Institute's Migratory Bird Center and lead author of the study.

The post Smithsonian scientists find declining rainfall is a major influence for migrating birds appeared first on Smithsonian Insider.

Discovery, the longest-serving orbiter in the space shuttle fleet, will be accepted into the Smithsonian’s National Air and Space Museum collection. The space shuttle has been the icon for American spaceflight for a generation, and Discovery has flown every type of mission during its 27-year career.

The post Space shuttle Discovery to be added to National Air and Space Museum collection appeared first on Smithsonian Insider.

An international team of astronomers has revealed details of a “super-exotic” exoplanet that would make the planet Pandora in the movie Avatar pale in comparison.

The post Astronomers unveil portrait of newly discovered “super-exotic super-Earth” appeared first on Smithsonian Insider.

The National Aeronautics and Space Administration has made available to the public a new online collection of images that capture the excitement of planetary exploration and the journey to understand the origin and evolution of the solar system.

The post Stunning high-resolution NASA images available online for public exhibits appeared first on Smithsonian Insider.

By compiling and comparing long-term data from stranding records and visual sighting records, both taken from nearly every ocean basin in the world, Pyenson verified that stranding records “faithfully reflect the number of species and the relative abundance” found in live surveys.

The post Stranding records are faithful reflection of live whale and dolphin populations, new study reveals appeared first on Smithsonian Insider.

Five billion years from now, our Milky Way galaxy will collide with the Andromeda galaxy. This will mark a moment of both destruction and creation. The galaxies will lose their separate identities as they merge into one. At the same time, cosmic clouds of gas and dust will smash together, triggering the birth of new stars.

The post The Spitzer Photo Atlas of Galactic “Train Wrecks” appeared first on Smithsonian Insider.

The National Zoo’s great cat program recently expanded with the arrival of two-and-a-half-year-old female Sumatran tiger, Damai, who is now out of quarantine and spending time outside in her exhibit where visitors can see her.

The post Damai, a two-and-a-half-year-old female Sumatran tiger, makes her debut at the National Zoo appeared first on Smithsonian Insider.

The National Zoo has received a breeding pair of Asian small-clawed otters at Asia Trail for the first time. Mac, a three-year-old male from the Point Defiance Zoo in Tacoma, Wash., and Smidge, a five-year-old female from the Columbus Zoo in Ohio, arrived in April and are now in their exhibit.

The post Keepers are optimistic about Zoo’s new breeding pair of Asian small-clawed otters appeared first on Smithsonian Insider.

The recent field of invasion biology faces a new challenge as 19 eminent ecologists issue a call to "end the bias against non-native species" in the journal Nature.

The post Is ecology biased against non-native species? appeared first on Smithsonian Insider.

Now, a new study of hellbenders by scientists at the Smithsonian Conservation Biology Institute will place these amphibians at the center of the conservation of Appalachian salamanders.

The post Will global warming be hell on the hellbender? Smithsonian study aims to find out. appeared first on Smithsonian Insider.

What Google is attempting for books, the University of California, Berkeley, plans to do for the world's vertebrate specimens: store them in "the cloud."

The post New “cloud-based” storage initiative to make vertebrate research collections available worldwide appeared first on Smithsonian Insider.

For the first time in decades, researchers have found a new bird species in the United States. Based on a specimen collected in 1963 on Midway Atoll, Northwestern Hawaiian Islands, biologists have described a new species of seabird, Bryan’s shearwater

The post Bryan’s shearwater, new Hawaiian seabird species, discovered appeared first on Smithsonian Insider.

Just as people use airplanes to fly overseas, marine snails may use birds to fly over land,” said Mark Torchin, staff scientist at the Smithsonian.

The post Hitchhiking snails fly from ocean to ocean appeared first on Smithsonian Insider.

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.

Smithsonian scientists and collaborators have determined the evolutionary family tree for one of the most strikingly diverse and endangered bird families in the world, the Hawaiian honeycreepers.

The post Complete evolutionary tree of the Hawaiian honeycreepers traced by Smithsonian scientists, collaborators appeared first on Smithsonian Insider.

Researchers who will study the microbial communities living on the skins of frogs that are surviving the fungal scourge of chytridiomycosis, deadly to the frogs.

The post Research team to explore how microbial diversity defends against disease appeared first on Smithsonian Insider.

A fragment of whale rib found in a North Carolina strip mine is offering scientists a rare glimpse at the interactions between prehistoric sharks and whales some 3- to 4- million years ago during the Pliocene.

The post Details of ancient shark attack preserved in fossil whale bone appeared first on Smithsonian Insider.

Astronomers are confident the Cygnus X-1 system contains a black hole, and with these latest studies they have remarkably precise values of its mass, spin, and distance from Earth.

The post New details on birth of black hole Cygnus X-1 revealed by Chandra X-ray Observatory appeared first on Smithsonian Insider.

Ornithologists Carla Dove and Storrs Olson used 700- to 1,100-year-old feathers from a long extinct species of Hawaiian ibis to help determine the bird’s place in the ibis family tree. The feathers are the only known plumage of any of the prehistorically extinct birds that once inhabited the Hawaiian Islands.

The post Fossil feathers from a Hawaiian cave help reveal lineage of extinct, flightless ibis appeared first on Smithsonian Insider.

New research on tiny spiders has revealed that their brains are so large that they fill their body cavities and overflow into their legs, say a team of scientists at the Smithsonian Tropical Research Institute in Panama.

The post Brains of tiny spiders fill their body cavities and legs, Smithsonian researchers discover appeared first on Smithsonian Insider.

In 2011, scholars from three institutions—National Museum of American History Curators Carlene Stephens and Shari Stout, Library of Congress Digital Conversion Specialist Peter Alyea and Lawrence Berkeley National Laboratory Scientists Carl Haber and Earl Cornell—came together in a newly designed preservation laboratory at the Library of Congress to recover sound from those recordings made more than 100 years ago.

The post Digital technology allows Alexander Graham Bell’s 1880s disc recordings to be played again appeared first on Smithsonian Insider.

A newly described species of toothed whale that lived some 3-4 million years ago during the Pliocene, is causing scientists to reconsider what is known about its living cold-water relatives: narwhals and belugas.

The post New fossil whale species raises mystery regarding why narwhals and belugas live only in cold water appeared first on Smithsonian Insider.

A baby boom is underway at the Smithsonian’s National Zoo. Two Guam rail (Gallirallus owstoni) chicks hatched March 3 and 4; they join six others in the Zoo’s collection—three of which live at the Smithsonian Conservation Biology Institute in Front Royal, Va.

The post Extremely rare Guam rails hatch at the Smithsonian’s National Zoo appeared first on Smithsonian Insider.

A new X-ray study of the remains of an exploded star indicates that the supernova that disrupted the massive star may have turned it inside out in the process.

The post Remains of exploded star indicate supernova turned it inside out appeared first on Smithsonian Insider.

The snakes are not only eating the area’s birds, but also the birds’ eggs straight from the nest.

The post Invasive pythons in Florida now stealing bird eggs straight from the nest appeared first on Smithsonian Insider.

Recently, after examining hundreds of photos taken by camera traps set-up to monitor clouded leopards in the park, three Smithsonian researchers say Khao Yai also is quite popular with a different kind of visitor: poachers.

The post Poachers at large in Thailand’s nature reserves despite ranger outposts appeared first on Smithsonian Insider.