Microcrystal delivery methods are pivotal in the use of serial femtosecond crystallography (SFX) to resolve the macromolecular structures of proteins. Here, the development of a novel technique and instruments for efficiently delivering microcrystals for SFX are presented. The new method, which relies on a one-dimensional fixed-target system that includes a microcrystal container, consumes an extremely low amount of sample compared with conventional two-dimensional fixed-target techniques at ambient temperature. This novel system can deliver soluble microcrystals without highly viscous carrier media and, moreover, can be used as a microcrystal growth device for SFX. Diffraction data collection utilizing this advanced technique along with a real-time visual servo scan system has been successfully demonstrated for the structure determination of proteinase K microcrystals at 1.85 Å resolution.

By using small-angle neutron scattering (SANS) reinforced by scanning electron microscopy, the fine structure of catalysts for polymer electrolyte fuel cells has been investigated. The experimental data resulting from contrast variation with mixed light and heavy water (H2O/D2O) are well described by a core–shell model with fluctuations in concentration between water and Nafion.

An attempt has been made to combine small-angle scattering of X-rays or neutrons with scanning electron microscopy in reciprocal space, in order to establish a structural analysis method covering a wide range of sizes from micro- to macro-scales.

This article describes rational strategies for the optimization of crystal growth using precise in situ control of the temperature and chemical composition of the crystallization solution through dialysis, to generate crystals of the specific sizes required for different downstream structure determination approaches.

Crystal structure and microscopic optical properties of anthracene derivative compounds have been investigated by single-crystal synchrotron X-ray diffraction, laser confocal microscopy and fluorescence lifetime imaging microscopy.

The structure of a 22-base-pair RNA helix with mismatched pyrimidine base pairs is reported. The helix contains two symmetry-related CUG sequences: a triplet-repeat motif implicated in myotonic dystrophy type 1. The CUG repeat contains a U–U mismatch sandwiched between Watson–Crick pairs. Additionally, the center of the helix contains a dimerized UUCG motif with tandem pyrimidine (U–C/C–U) mismatches flanked by U–G wobble pairs. This region of the structure is significantly different from previously observed structures that share the same sequence and neighboring base pairs. The tandem pyrimidine mismatches are unusual and display sheared, cross-strand stacking geometries that locally constrict the helical width, a type of stacking previously associated with purines in internal loops. Thus, pyrimidine-rich regions of RNA have a high degree of structural diversity.

For a thousand years, Cyprus was divided into at least 10 autonomous states. The inhabitants spoke three languages: Greek, Phoenician, and Eteocypriot, the original language […]

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Snowflake Study through Photomicrography, 1890 Wilson A. Bentley became fascinated with the crystalline structure of individual snowflakes on his parent’s Vermont farm. By adapting a […]

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A new genetic study by a team of Cuban and American researchers confirms that American crocodiles are hybridizing with wild populations of critically endangered Cuban crocodiles, which may cause a population decline of this species found only in the Cuban Archipelago.

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The Life and Morals of Jesus of Nazareth, more commonly known as the Jefferson bible, is a volume created by Thomas Jefferson containing passages he […]

The post Unlocking the mysteries of Jefferson’s bible with high-tech analysis and microscopic testing appeared first on Smithsonian Insider.

The Zoo’s Smithsonian Conservation Biology Institute in Front Royal, Va., is celebrating the recent hatching of two Micronesian kingfisher (Todiramphus c. cinnamominus) chicks, a female and male, born July 25 and Aug. 20, respectively.

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University of Florida and Smithsonian Tropical Research Institute scientists describe a new 20-foot extinct species of crocodile discovered in the same Colombian coal mine with Titanoboa, the world’s largest snake.

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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.

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  This photo shows developing embryonic cells of the coral species Acropora tenuis, from the Great Barrier Reef in Australia. Researchers from the Smithsonian Conservation […]

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Scientists studying genetic variation and gene flow in a population of tortoises (Gopherus agassizii) in California’s Mojave Desert, were surprised recently to discover that two roads built in the desert in the 1970s had a noticeable impact on the population’s genetic structure.

The post Why did the tortoise cross the road? A recent study indicates few do. appeared first on Smithsonian Insider.

The specimen’s skull measures 24 centimeters, roughly the size of a regulation NFL football. The shell which was recovered nearby – and is believed to belong to the same species – measures 172 centimeters, or about 5 feet 7 inches, long.

The post Giant prehistoric turtle from Colombia chomped everything in sight–including crocodiles! appeared first on Smithsonian Insider.

Two Cuban crocodiles were born at the Smithsonian’s National Zoo on July 6 and 14 and they are among the most genetically valuable in the […]

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The uplift of the Isthmus of Panama 2.6 million years ago formed a land-bridge that has long thought to be the crucial step in the […]

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Microbes that live in rice paddies, northern peat bogs and other previously unexpected environments are among the bacteria that can generate highly toxic methylmercury, researchers […]

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Hopes are high for Comet ISON, which has the potential to become the most spectacular comet seen in years. ISON is speeding through the inner […]

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  Tiny spherules pepper a sandy surface in this 3-centimeter (1.2-inch) square view of the Martian surface. The largest one is broken in half and […]

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The Smithsonian Conservation Biology Institute rung in 2014 with the hatching of the most endangered species in its collection—a Micronesian kingfisher—Jan. 1. The chick, whose […]

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One year ago, the olinguito (Bassaricyon neblina) stepped out of the forest shadows into the spotlight and onto the pages of science—the first carnivore species […]

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Human skin and gut microbes influence processes from digestion to disease resistance. Despite the fact that tropical forests are the most biodiverse terrestrial ecosystems on […]

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From bizarre bugs to penis spines on bats, our world is infinitely expanded when we look down the microscope! Check out the stories behind these […]

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The challenges of conceiving only get greater as we get older. But if you have some of the most prized genes within your entire species, […]

The post High hopes for 60 year-old crocodile to become mother again appeared first on Smithsonian Insider.

A new study published this week in the Proceedings of the Royal Society by scientists at the Smithsonian Conservation Biology Institute (SCBI) found unique communities […]

The post Golden Frogs with Unique Skin Microbes Survive Frog-Killing Fungus appeared first on Smithsonian Insider.

  In the store-rooms of the National Museum of American History curators recently discovered a small microscope made around 1750 by John Cuff (1708-1772), a […]

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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. […]

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In April 2015, after traveling for about half the age of the universe, a flood of powerful gamma rays from a distant galaxy slammed into […]

The post VERITAS Detects Gamma Rays from Galaxy Halfway Across the Visible Universe appeared first on Smithsonian Insider.

A bite mark on a homicide victim’s skin is not an unusual discovery. A criminal’s teeth marks are also occasionally found on food at a […]

The post Crime bite: DNA on half-eaten food may someday send crooks to jail appeared first on Smithsonian Insider.

The world’s most indestructible species, the tardigrade, an eight-legged micro-animal, also known as the water bear, will survive until the Sun dies, according to a […]

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Today’s cutting-edge laboratories rely on ultra-cold refrigeration to keep delicate cells like sperm viable for use in the future. But a new technique using microwaves […]

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Marine mammologist Matthew Leslie aims his crossbow from the bow of a moving boat at the dolphins riding the breaking waves below. A dolphin will […]

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The number of new X-ray crystallography-based submissions to the Protein Data Bank appears to be at the beginning of a decline, perhaps signalling an end to the era of the dominance of X-ray crystallography within structural biology. This letter, from the viewpoint of a young structural biologist, applies the Copernican method to the life expectancy of crystallography and asks whether the technique is still the mainstay of structural biology. A study of the rate of Protein Data Bank depositions allows a more nuanced analysis of the fortunes of macromolecular X-ray crystallography and shows that cryo-electron microscopy might now be outcompeting crystallography for new labour and talent, perhaps heralding a change in the landscape of the field.

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.

Yinlong Song, Yikan Zhang, Ying Pan, Jianfeng He, Yan Wang, Wei Chen, Jing Guo, Haiteng Deng, Yi Xue, Xianyang Fang, and Xin Liang

Microtubules dynamics is regulated by the plus end-tracking proteins (+TIPs) in cells. End binding protein 1 (EB1) acts as a master regulator in +TIPs networks by targeting microtubule growing ends and recruiting other factors. However, the molecular mechanism of how EB1 binds to microtubule ends with a high affinity remains to be an open question. Using single-molecule imaging, we show that the end-binding kinetics of EB1 changes along with the polymerizing and hydrolysis rate of tubulin dimers, confirming the binding of EB1 to GTP/GDP-Pi tubulin at microtubule growing ends. The affinity of wild-type EB1 to these sites is higher than monomeric EB1 mutants, suggesting that two CH domains in the dimer contribute to the end-binding. Introducing phosphomimicking mutations into the linker domain of EB1 weakens the end-binding affinity and confers a more curved conformation to EB1 dimer without compromising dimerization, suggesting that the overall architecture of EB1 is important for the end-binding affinity. Taken together, our results provide insights into understanding how the high-affinity end-binding of EB1 can be achieved and how this activity may be regulated in cells.

Laura O'Regan, Giancarlo Barone, Rozita Adib, Chang Gok Woo, Hui Jeong Jeong, Emily L. Richardson, Mark W. Richards, Patricia A.J. Muller, Spencer J. Collis, Dean A. Fennell, Jene Choi, Richard Bayliss, and Andrew M. Fry

EML4-ALK is an oncogenic fusion present in ~5% non-small cell lung cancers. However, alternative breakpoints in the EML4 gene lead to distinct variants with different patient outcomes. Here, we show in cell models that EML4-ALK variant 3 (V3), which is linked to accelerated metastatic spread, causes microtubule stabilization, formation of extended cytoplasmic protrusions and increased cell migration. It also recruits the NEK9 and NEK7 kinase to microtubules via the N-terminal EML4 microtubule-binding region. Overexpression of wild-type EML4 as well as constitutive activation of NEK9 also perturb cell morphology and accelerate migration in a microtubule-dependent manner that requires the downstream kinase NEK7 but not ALK activity. Strikingly, elevated NEK9 expression is associated with reduced progression-free survival in EML4-ALK patients. Hence, we propose that EML4-ALK V3 promotes microtubule stabilization through NEK9 and NEK7 leading to increased cell migration. This represents a novel actionable pathway that could drive metastatic disease progression in EML4-ALK lung cancer.

Yung-An Huang, Chih-Hsuan Hsu, Ho-Chieh Chiu, Pei-Yu Hsi, Chris T. Ho, Wei-Lun Lo, and Eric Hwang

Microtubule (MT) is the most abundant cytoskeleton in neurons and controls multiple facets of their development. While the MT-organizing center (MTOC) in mitotic cells is typically located at the centrosome, MTOC in neurons switches to non-centrosomal sites. A handful of cellular components have been shown to promote non-centrosomal MT (ncMT) formation in neurons, yet the regulation mechanism remains unknown. Here we demonstrate that the small GTPase Ran is a key regulator of ncMTs in neurons. Using an optogenetic tool that enables light-induced local production of RanGTP, we demonstrate that RanGTP promotes ncMT plus-end growth along the neurite. Additionally, we discovered that actin waves drive the anterograde transport of RanGTP. Pharmacological disruption of actin waves abolishes the enrichment of RanGTP and reduces growing ncMT plus-ends at the neurite tip. These observations identify a novel regulation mechanism of ncMTs and pinpoint an indirect connection between the actin and MT cytoskeletons in neurons.

Xian Hu, Salma Jalal, Michael Sheetz, Oddmund Bakke, and Felix Margadant

Despite progress made in confocal microscopy, even fast systems still have insufficient temporal resolution for detailed live cell volume imaging, such as tracking rapid movement of membrane vesicles in three-dimensional space. Depending on the shortfall, this may result in undersampling and/or motion artifacts that ultimately limit the quality of the imaging data. By sacrificing detailed information in the Z-direction, we propose a new imaging modality that involves capturing fast "projections" from the field of depth which shortens imaging time by approximately an order of magnitude as compared to standard volumetric confocal imaging. With faster imaging, radiation exposure to the sample is reduced, resulting in less fluorophore photobleaching and potential photodamage. The implementation minimally requires two synchronized control signals that drive a piezo stage and trigger the camera exposure. The device generating the signals has been tested on spinning disk confocals and instant structured-illumination-microscopy (iSIM) microscopes. Our calibration images show that the approach provides highly repeatable and stable imaging conditions that enable photometric measurements of the acquired data, in both standard live imaging and super-resolution modes.

Ana Loncar, Sergio A. Rincon, Manuel Lera Ramirez, Anne Paoletti, and Phong T. Tran

To segregate the chromosomes faithfully during cell division, cells assemble a spindle that captures the kinetochores and pulls them towards opposite poles. Proper spindle function requires correct interplay between microtubule motors and non-motor proteins. Defects in spindle assembly or changes in spindle dynamics are associated with diseases like cancer or developmental disorders. Here we compared mitotic and meiotic spindles in fission yeast. We show that even though mitotic and meiotic spindles undergo the typical three phases of spindle elongation, they have distinct features. We found that the relative concentration of kinesin-14 Pkl1 is decreased in meiosis I compared to mitosis, while the concentration of kinesin-5 Cut7 remains constant. We identified the second kinesin-14 Klp2 and microtubule dynamics as factors necessary for proper meiotic spindle assembly. This work defines differences between mitotic and meiotic spindles in fission yeast, and provides prospect for future comparative studies.

Odile Madden knows a lot about plastic. A materials scientist with the Smithsonian Museum Conservation Institute, she has spent the past eight years studying plastics […]

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Monday, Aug. 21 was an unusual day across North America. Early in the morning, families, colleagues and tourists were searching for special solar glasses with […]

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A mysterious nocturnal animal was leaving its tracks on the delicate mirrors of the telescopes at the Smithsonian's Whipple Observatory in Arizona. With a little ingenuity and a live trap, the mystery was solved. The visitor proved to be a ringtail cat, a member of the raccoon family.

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Tom Crouch, Senior curator in the National Air and Space Museum's Aeronautics Division, discusses Thaddeus Lowe and the birth of American aerial reconnaissance during the Civil War. This presentation was recorded on May 11, 2011 on the National Mall.

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The post Japanese acrobats ca. 1927, footage from the Smithsonian’s Human Studies Film Archive appeared first on Smithsonian Insider.

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Meg studies intergroup competition in white‐faced capuchin monkeys by tracking them through radio telemetry collars and observing their behaviors.

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myVolcano is a crowd-sourcing app that enables you to share your photographs and descriptions of volcanic hazards, as well as collecting samples and measurements of […]

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