Researchers from the University of California, Santa Cruz, using macromolecular crystallography Beam Line 9-1 at SSRL have determined the three-dimensional structure of an RNA enzyme, or "ribozyme," that carries out a fundamental reaction required to make new RNA molecules. Their results provide insight into what may have been the first self-replicating molecule to arise billions of years ago on the evolutionary path toward the emergence of life. The findings are published in the March 16 issue of the journal Science.
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.
A team of researchers working at SSRL has determined the atomic structure of an assemblage of fiber-forming proteins found in the cell membranes of many dangerous types of bacteria. The protein, called pilin, assembles into filamentous organelles called Type IV pili found on the surfaces of most Gram-negative bacteria. Type IV pili plays a central role in how these bacterial pathogens infect a host and are involved in cellular functions such as motility, adhesion, microcolony formation and uptake of DNA and specific filamentous phage.
Botulinum neurotoxin is produced by the bacteria Clostridium botulinum and is the most potent toxin known, inducing a potentially fatal paralysis known as "botulism." Botulism can occur in a number of ways, including infection through open wounds or in the intestinal tract, or after consuming contaminated food in which toxin has been produced. In the USA, infant botulism is the most common manifestation of the disease-some speculate whether its prevalence is linked to sudden infant death syndrome. On the other hand, these neurotoxins have also become a powerful therapeutic tool for treating a variety of neurological, ophthalmic, and other disorders manifested by abnormal, excessive, or inappropriate muscle contractions.
In 1974, while sinking irrigation wells in the Chinese province of Shaanxi, a group of farmers made an astonishing archeological discovery. Buried beneath their feet stood a contingent of 8,000 life-sized terra cotta warriors and their horses, facing east, ready for battle. The figures, later found to be more than 2,000 years old, were accompanied by weapons, real chariots, and objects of jade and bone. It was later determined that this army was built to protect the tomb of the first emperor of the Qin dynasty, Shi Huang Di.
Botulinum neurotoxin is produced by the bacteria Clostridium botulinum and is the most potent toxin known, inducing a potentially fatal paralysis known as "botulism." Botulism can occur in a number of ways, including infection through open wounds or in the intestinal tract, or after consuming contaminated food in which toxin has been produced. In the USA, infant botulism is the most common manifestation of the disease-some speculate whether its prevalence is linked to sudden infant death syndrome. On the other hand, these neurotoxins have also become a powerful therapeutic tool for treating a variety of neurological, ophthalmic, and other disorders manifested by abnormal, excessive, or inappropriate muscle contractions.
In a recent experiment performed at SLAC and reported in the February 2 issue of Science, David Fritz and his SPPS colleagues have obtained our first direct view of the motion of atoms inside a crystal. This feat requires simultaneous Angstrom spatial and femtosecond temporal resolution. Synchrotrons have been providing subatomic resolution for decades, and ultrafast lasers have been capable of sub-picosecond timing for more than twenty years; but SPPS was the first instrument to combine both.
The FeFe-hydrogenases are of great interest because they can catalyze both the forward and reversed dihydrogen uptake/evolution reactions. Under optimal conditions a single molecule of FeFe-hydrogenase can produce approximately 9000 molecules of hydrogen per second. This translates into a theoretical capacity for refueling the hydrogen tank of the Space Shuttle within 30 minutes. Thus, hydrogenases are considered as desirable biological targets for hydrogen-based energy production and utilization technologies.
Scientists at SSRL have demonstrated a novel approach for improving the efficiency of an x-ray microscopy technique that may in particular prove beneficial for imaging radiation-sensitive objects such as biological samples. The findings, published in the October 2006 issue of Applied Physics Letters, should enhance imaging of sensitive samples and improve imaging with future ultra-short pulsed light sources, such as the Linac Coherent Light Source.
Scientists have discovered a gene for a protein that regulates the cellular response to copper in the bacterium that causes tuberculosis. These findings, reported in the January issue of Nature Chemical Biology, explain how a wide variety of bacteria control copper concentrations within their cells, and this understanding could lead to new treatments for tuberculosis.
Researchers from the University of Washington working at SSRL have solved the structure of a protein complex that may one day be exploited to combat drug-resistant strands of the parasite that causes malaria, Plasmodium. Malaria, one of the most devastating diseases worldwide, infects 300 to 500 million people and causes about 2 million deaths each year.