During evolution, organisms added new domains to tRNA synthetases, which are believed to enable additional functions beyond protein synthesis. For the very first time researchers have established an essential role for an appended domain of tRNA synthetase in organisms.
Approximately 1,700 scientists visit SSRL annually to conduct experiments in broad disciplines including life sciences, materials, environmental science, and accelerator physics. Science highlights featured here and in our monthly newsletter, Headlines, increase the visibility of user science as well as the important contribution of SSRL in facilitating basic and applied scientific research. Many of these scientific highlights have been included in reports to funding agencies and have been picked up by other media. Users are strongly encouraged to contact us when exciting results are about to be published. We can work with users and the SLAC Office of Communication to develop the story and to communicate user research findings to a much broader audience. Visit SSRL Publications for a list of the hundreds of SSRL-related scientific papers published annually. Contact us to add your most recent publications to this collection.
July 2013
Macromolecular Crystallography
BL7-1
July 2013
Argonaute proteins play an important role in the biological process of RNA interference (RNAi). Scientists have now determined the crystal structure of human Argonaute2, thereby making progress toward a detailed understanding of Ago2 interactions with target RNA which may benefit the design of novel RNAi therapeutics.
Macromolecular Crystallography
BL11-1
July 2013
For most modern-day terrestrial life, oxygen has become indispensable. At the heart of oxygenic photosynthesis is the production of oxygen from water – a process mediated by the water-splitting manganese cluster of Photosystem II. Little is known about how oxygenic photosynthesis originally evolved, although some have hypothesized a manganese-oxidizing photosystem as a precursor step.
BL2-3, BL4-1, BL10-2
June 2013
Cells bind each other using specialized cell surface adhesion complexes called adherens junctions. These complexes direct the formation of tight, Velcro-like contacts that are essential for the development, architecture, maintenance, and function of tissues in all higher organisms. Exactly how this cell to cell binding is accomplished has not been fully understood. Researchers from the Florida campus of The Scripps Research Institute (TSRI) have now solved a piece of this puzzle by determining the structure of α-catenin using SSRL’s Beam Line 11-1.
Macromolecular Crystallography
BL11-1
June 2013
Hydrogen gas is produced in chemical reactions between anoxic water and iron-rich rocks at temperatures above 200°C – conditions too hot to support life. However, at hydrothermal vents or hot springs, where hydrogen-rich fluids mix with cooler waters and temperatures have dropped sufficiently, hydrogen-consuming organisms can survive. Less is known about the amount and mechanism of hydrogen production from water-rock reactions occurring at temperatures within the temperature limits of life (≤122°C) and the potential for these reactions to support in situ microbial life. Given the large expanse of the Earth’s crust that likely interacts with water under these cooler conditions, it is possible that these low-temperature reactions could sustain extensive subsurface microbial communities away from Earth’s hot spots.
Researchers have used SSRL’s BL2-3 microXAS imaging instrument to study what happens in detail as hydrogen is produced at low temperatures when powdered rocks and minerals are submerged in anoxic water at 55°C and 100°C for a period of 100 days. They found that spinels are key in hydrogen production, acting as mediators in the electron transfer between Fe2+ and water and thus play an important role in hydrogen production during low-temperature reactions.
BL2-3
May 2013
Li-ion batteries are key devices in the effort to develop efficient chemical energy storage from sustainable energy sources. However, any effort to optimize battery performance requires a deeper understanding of the fundamental mechanisms of diffusion and phase transformation in battery electrodes.
BL6-2
May 2013
Aminoacyl-tRNA synthetases are required in all three domains of life to add the correct amino acid to its cognate tRNA, an essential step in protein synthesis. Despite their importance, no structure had been reported for any full-length eukaryotic, glutaminyl-tRNA synthetase (GlnRS), although structural data for two prokaryotic GlnRS species exists.
Macromolecular Crystallography, Biological Small-angle X-ray Scattering (BioSAXS)
BL4-2, BL11-1
April 2013
Cys-loop receptors in eukaryotic cells control fast synaptic transmission and are important targets for various therapeutics which include general anesthetics. Although technical challenges have limited the determination of high-resolution structures for Cys-loop receptors, researchers from the University of Pittsburgh School of Medicine have taken advantage of two homologous proteins: the pentameric ligand-gated ion channels (pLGICs) found in the bacterium Erwinia chrysanthemi (ELIC) and the cyanobacterium Gloebacter violaceus (GLIC). The researchers carried out crystallographic studies of these pLGICs on SSRL Beam Line 12-2, investigating the structural underpinnings of the pLGIC activation process and the structural basis of anesthetic modulation of pLGICs.
Macromolecular Crystallography
BL12-2
April 2013
A study, recently published in PLoS ONE by researchers from Cornell University, Hospital for Special Surgery, and SSRL, describes nanoscale visualization of micro-damage in cortical bone tissue using x-ray negative staining and synchrotron-based x-ray imaging. The first study to examine bone damage at the nanoscale using full-field x-ray imaging in cortical bone, it provides new insights into bone damage and propagation of fractures.
BL6-2c
March 2013
For the first time, ultrafast x-ray scattering and spectroscopic measurements carried out at SSRL, the Advanced Light Source (ALS) and the Advanced Photon Source (APS) captured the atomic-level dynamics of a superionic nanocrystal as it transformed.
X-ray scattering
BL2-3, BL13-3
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