Aerobic thermoacidophilic archaea belonging to the genus Sulfolobus harbor peroxiredoxins, thiol-dependent peroxidases that assist in protecting the cells from oxidative damage. Here, the crystal structure of the 1-Cys peroxiredoxin from Sulfolobus islandicus, named 1-Cys SiPrx, is presented. A 2.75 Å resolution data set was collected from a crystal belonging to space group P212121, with unit-cell parameters a = 86.8, b = 159.1, c = 189.3 Å, α = β = γ = 90°. The structure was solved by molecular replacement using the homologous Aeropyrum pernix peroxiredoxin (ApPrx) structure as a search model. In the crystal structure, 1-Cys SiPrx assembles into a ring-shaped decamer composed of five homodimers. This quaternary structure corresponds to the oligomeric state of the protein in solution, as observed by size-exclusion chromatography. 1-Cys SiPrx harbors only a single cysteine, which is the peroxidatic cysteine, and lacks both of the cysteines that are highly conserved in the C-terminal arm domain in other archaeal Prx6-subfamily proteins such as ApPrx and that are involved in the association of dimers into higher-molecular-weight decamers and dodecamers. It is thus concluded that the Sulfolobus Prx6-subfamily protein undergoes decamerization independently of arm-domain cysteines.

A recent study of dog bones excavated from archaeological sites on the Channel Islands of California has cast new light on the past ecology of the islands and the impact that domestic dogs--brought to the islands by Native Americans more than 6,000 years ago—may have once had on the islands’ animals and ecosystems.

The post Dog bones reveal ecological history of California’s Channel Islands appeared first on Smithsonian Insider.

Long before dawn on a recent morning, Katie Milton and a group of stalwart volunteers, each armed with flashlight and compass, spread out into the jungle to take up positions at 35 listening stations marked on maps of the island.

The post Census reveals 1,200 howler monkeys living on Barro Colorado Island 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.

Take to the water with this behind-the-scenes video about Maryland blue crab research at the Smithsonian's Environmental Research Center. Fisheries Ecologist Eric Johnson takes viewers on a journey along the Rhode River to show how scientists tag and monitor Maryland blue crabs in the Chesapeake Bay watershed.

The post Maryland Blue Crab Science at the Smithsonian appeared first on Smithsonian Insider.

Researchers at the Smithsonian Conservation Biology Institute conducted three different kinds of genetics tests and all yielded the same result—the Galapagos seabirds have been genetically different from the magnificent frigatebirds elsewhere for more than half a million years.

The post Genetic surprise: Magnificent frigatebird living on Galapagos Islands is distinct species appeared first on Smithsonian Insider.

On the Smithsonian Tropical Research Institute's Barro Colorado Island in the Panama Canal, staff members are taking down a network of seven tall Automated Radio Telemetry System towers used to track animals wearing radio-transmitters. Scientists on the island are switching to GPS and camera trap systems to produce more data with less infrastructure.

The post GPS and camera traps to replace radio antennas in tracking animals on Barro Colorado Island appeared first on Smithsonian Insider.

The tiger reserves of Asia could support more than 10,000 wild tigers – three times the current number – if they are managed as large-scale […]

The post Tiger numbers could triple if large-scale landscapes are protected appeared first on Smithsonian Insider.

Evidence for a diversified sea-based economy among North American inhabitants dating from 12,200 to 11,400 years ago is emerging from three sites on California's Channel Islands.

The post New archaeological evidence reveals California’s Channel Islands as North America’s earliest seafaring economy appeared first on Smithsonian Insider.

This is the first report of this invasive species in this area, and may indicate a recent range expansion of the snakehead population.

The post Smithsonian team finds northern snakehead fish in Maryland’s Rhode River appeared first on Smithsonian Insider.

A new study on the dodo’s island home of Mauritius in the Indian Ocean, paints a picture of this unusual bird as an intrepid survivor on par with the giant tortoise for its resiliency.

The post Dodo bird a resilient island survivor before the arrival of humans, study reveals appeared first on Smithsonian Insider.

The same device used to detect early warning signs of heart disease in humans will now benefit two male sub-adult gorillas at the Smithsonian’s National Zoo.

The post Heart disease study to benefit lowland gorillas at the National Zoo appeared first on Smithsonian Insider.

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.

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.

Smithsonian Conservation Biology Institute scientists and collaborators have found that the island scrub-jay’s population on Santa Cruz Island—its only habitat—is significantly smaller than previously believed […]

The post New count reveals scrub-jay on Santa Cruz Island is among rarest bird species in the U.S. appeared first on Smithsonian Insider.

The Mortlock Islands flying fox, a large, breadfruit-eating bat native to a few remote and tiny Pacific islands, has long been regarded as one of […]

The post Scientists shine light on world’s least-studied bat: Mortlock Islands flying fox appeared first on Smithsonian Insider.

A groundbreaking study by Harvard University’s Harvard Forest and the Smithsonian Conservation Biology Institute reveals that, if left unchecked, recent trends in the loss of […]

The post Sprawl threatens water quality, climate protection, and land conservation in Massachusetts appeared first on Smithsonian Insider.

Tasty and easy to find, the heath hen was a favorite dish of America’s colonial settlers. This beautiful little bird, however, was no match for […]

The post Urban landscapes becoming increasingly bird-unfriendly appeared first on Smithsonian Insider.

A new DNA study of ancient corn kernels and cobs from archaeological sites across North America has settled a long debate as to exactly where […]

The post Corn entered Southwest U.S. first along highland route, DNA shows appeared first on Smithsonian Insider.

California’s Channel Islands are located dozens of miles west of the state’s coast and surrounded by Pacific waters, yet they too are experiencing the same […]

The post Drought slows wildlife reproduction on California’s Channel Islands 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.

A one-cubic-foot approach to studying biodiversity as showcased in the new Biocube exhibit at the Smithsonian’s National Museum of Natural History has led to the […]

The post New parasitic crab species discovered during Smithsonian Biocube work in Solomon Islands appeared first on Smithsonian Insider.

NASA’s InSight probe, scheduled to land on the surface of Mars in November 2018, will be boring. Boring a hole, that is. It will drill […]

The post ISO: a boring Martian landing spot for NASA’s InSight probe appeared first on Smithsonian Insider.

To fully know a species and develop sound conservation efforts, its full life cycle must be understood. But tracking small migratory birds for thousands of […]

The post Keeping Track of Kirtland’s Warbler All Year Long―A Scientific First appeared first on Smithsonian Insider.

Tidal Freshwater Wetlands focuses on wetlands found in North America and Europe near the mouths of rivers that flow into estuaries like the Chesapeake Bay.

The post New book reveals tidal freshwater wetlands are on frontlines of global change appeared first on Smithsonian Insider.

The number and diversity of tectonic landforms in our solar system “is truly remarkable,” Watters and Schultz write. Photographs of these structures have stimulated a range of scholarly investigations.

The post Book Review: Planetary Tectonics examines otherworldly landforms appeared first on Smithsonian Insider.

During a press conference Friday, July 22 at the Smithsonian's National Air and Space Museum, NASA announced that Gale Crater will be the landing site for the Mars Science Laboratory. Scheduled to launch in late 2011 and arrive at Mars in August 2012, the Mars Science Laboratory is a rover that will assess the planet’s “habitability”—if it ever was, or is today, an environment able to support microbial life.

The post Gale Crater to be landing site for NASA’s Mars Science Laboratory appeared first on Smithsonian Insider.

The new island visible in the satellite photograph is the top of a giant shield volcano located on the rift axis in the Red Sea where the continental plates of Africa and Arabia are pulling apart.

The post A hot new island has just surfaced in the Red Sea. What’s going on? Smithsonian scientists explain. appeared first on Smithsonian Insider.

The humble salamander may provide evidence to support a controversial claim that North and South America were joined together much earlier than previously thought. The […]

The post Salamander DNA reveals evidence of older land connection between Central and South America appeared first on Smithsonian Insider.

The main mass of a rare meteorite that exploded over California’s Sierra foothills in April 2012 will be preserved for current and future scientific discoveries, […]

The post Pieces of rare meteorite land at five different academic institutions appeared first on Smithsonian Insider.

Left to themselves, coastal wetlands can adapt to sea-level rise. But humans could be sabotaging some of their best defenses, according to a review paper […]

The post Wetlands sinking with human-built structures appeared first on Smithsonian Insider.

Forensic anthropologists from the Smithsonian's National Museum of Natural History discover African remains at a Colonial burial site in Maryland. Follow them as they study the remains, reconstruct the face and body, and share what they learn about the African experience in the Chesapeake in the 1600s.

The post Smithsonian team examines African remains from a colonial burial site in Maryland appeared first on Smithsonian Insider.

Rick Wunderman of the Global Volcanism Program at the Smithsonian's National Museum of Natural History talks about the current volcanic activity in Iceland.

The post Smithsonian volcanologist Rick Wunderman talks about volcanos and the recent eruptions in Iceland appeared first on Smithsonian Insider.

What determines the variety of trees in a tropical forest? Is it the seed size? Perhaps seed-hungry animals? And what happens to forests that are being drastically changed by humans? Smithsonian Tropical Research Center Botanist, Helene Muller Landau, talks about her attempt to find answers to these questions.

The post Meet Our Scientist: Helene Muller Landau – Tropical Forest Science appeared first on Smithsonian Insider.

The post Roland Kays, curator of mammals at the New York State Museum, discusses a new Smithsonian Website for sharing camera-trap images of wild animals appeared first on Smithsonian Insider.

The post Barro Colorado Island: The Smithsonian’s research outpost in the Panama Canal appeared first on Smithsonian Insider.

A team of some 30 taxonomists, many from the Smithsonian Tropical Research Institute, accompanied by renowned photographer Christian Ziegler, conduct a week-long bioblitz on Cobia […]

The post Bioblitz!! Cobia Island, Panama appeared first on Smithsonian Insider.

The Weeping Goldsmith, written as a first-person narrative, follows Botanist John Kress through nine years as he surveys Myanmar’s teak forests, bamboo thickets, timber plantations, rivers and mangroves to document its incredible botanical biodiversity.

The post Smithsonian botanist writes book on his discoveries in the secret land of Myanmar appeared first on Smithsonian Insider.

The post Cool science is being carried out on a Smithsonian island in the Panama Canal appeared first on Smithsonian Insider.

Smithsonian plant physiologist Bert Drake has studied one wetland's response to climate change for more than two decades. He gives a tour of the field experiment and explains some of the findings.

The post On the Chesapeake Bay, Smithsonian plant physiologist Bert Drake has been studying one wetland’s response to climate change for more than two decades. appeared first on Smithsonian Insider.

Recent botanical exploration efforts in the rugged Marquesas Islands (French Polynesia) have increased the known flora of the archipelago by an impressive 20 percent. Field research and collecting in conjunction with the Vascular Flora of the Marquesas Islands and Flore de la Polynesie française projects have yielded 62 new species of ferns and flowering plants bringing the total native species to 360, of which 18 are newly described and illustrated in a special issue of PhytoKeys.

The post Marquesas Islands in French Polynesia yield 18 new species of rare ferns and flowering plants appeared first on Smithsonian Insider.

Despite many laws to protect it, a new survey reveals wild ginseng in Maryland is on the decline.

The post Wild ginseng in steep decline in Maryland, survey reveals: Q&A with Smithsonian botanist Christopher Puttock appeared first on Smithsonian Insider.

Under elevated carbon dioxide levels, wetland plants can absorb up to 32 percent more carbon than they do at current levels, according to a 19-year […]

The post High CO2 spurs wetlands to absorb more carbon appeared first on Smithsonian Insider.

How much is a wetland worth? It’s a question that has plagued policymakers, scientists and other leaders looking to protect their communities and slow down […]

The post New report enables creation of carbon credits for restored wetlands appeared first on Smithsonian Insider.

At the approach of a hungry parrot snake, a tree frog egg transforms from a haven to a prison. With no parent to offer protection, […]

The post Mystery solved: frogs use snout glands in emergency jail break appeared first on Smithsonian Insider.

This Earth Day weekend in Washington, D.C., the Smithsonian is convening the first Earth Optimism Summit. The three-day event, taking place April 21–23, will look […]

The post Earth Optimism: Smithsonian’s “Agua Salud” Project restores degraded land with forest appeared first on Smithsonian Insider.

The Open Banking Report 2019 clarifies the role of key key-players in a post-September 14th world and assesses how the landscape has shifted within Europe and beyond.

A Landau theory for the wurtzite-based heterovalent ternary semiconductor ZnSnN2 is developed and a first-order reconstructive phase transition is proposed as the cause of observed crystal structure disorder. The model infers that the phase transition is paraelectric to antiferroelectric.

The U.S. Department of Energy should place a higher priority on developing an accurate and actionable inventory of agency-owned or managed properties that can be leased or sold for energy development, says a new report from the National Academies of Sciences, Engineering, and Medicine.