Wrapping up DNA for a Cell

All eukaryotic genomes, including the human genome, must be packaged into the nuclei of cells while still remaining readily accessible — and researchers have now taken a step closer to understanding how this feat is accomplished. Feng Song and colleagues used cryo-electron microscopy to show how DNA tightly wrapped around nucleosomes, which are composed of special packaging proteins called histones, results in a basic form of chromatin.

Read more about this research from the 25 April issue of Science here.

[Video © Institute of Biophysics, Chinese Academy of Sciences. Please click here for more information.]

© 2014 American Association for the Advancement of Science. All Rights Reserved.

Ready for its Close-up: The Mitoribosome

Large biomolecules can be visualized at high resolution thanks to advances in detector technology, a new study reports. The study provides a very close look at the mitochondrial ribosome, the structure of which has been elusive, even while the structures of ribosomes from eukaryotes and bacteria have been determined.

Read more about this research from the 28 March issue of Science here.

[Image courtesy of Alexey Amunts and Lesley McKeane. Please click here for more information.]

© 2014 American Association for the Advancement of Science. All Rights Reserved.

Ready for its Close-up: The Mitoribosome

Large biomolecules can be visualized at high resolution thanks to advances in detector technology, a new study reports. The study provides a very close look at the mitochondrial ribosome, the structure of which has been elusive, even while the structures of ribosomes from eukaryotes and bacteria have been determined.

Read more about this research from the 28 March issue of Science here.

[Image courtesy of Alexey Amunts and Lesley McKeane. Please click here for more information.]

© 2014 American Association for the Advancement of Science. All Rights Reserved.

Don’t Eat Me: Synthetic Peptides Trick Immune System

Researchers have developed a synthetic molecule that allows foreign particles to escape immune system detection. The synthetic peptide could be used to improve drug delivery to tumors and enhance medical imaging technologies.

Read more about this research from the 20 February issue of Science here.

[Video courtesy of Kurtis Sensenig, University of Pennsylvania. Click here for caption information.]

© 2013 American Association for the Advancement of Science. All Rights Reserved.

New Study Takes the X-ray Laser One Step Further

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Researchers have shown that powerful, ultra-fast X-ray lasers like the kind highlighted in Science’s 2012 “Breakthrough of the Year” feature can determine the structures of tiny protein crystals — too fragile for conventional X-ray techniques — without damaging them. Now, Jan Kern and colleagues show that this method can be paired with X-ray emission spectroscopy to probe both the geometry and electronic structure of a sample.

Read more about this research from the 14 February issue of Science Express here.

[Image courtesy of J. Kern, LBNL. Click the image for more information.]

© 2013 American Association for the Advancement of Science. All Rights Reserved.

X-Ray Laser Pulses Reveal Key Parasite Enzyme

A new technique for determining a protein’s three-dimensional structure has revealed the inner workings of an important enzyme in Trypanosoma brucei, the parasite that causes sleeping sickness. Typically, researchers determine these structures by shining an X-ray beam onto a protein crystal. But, it’s difficult to grow crystals that are large enough to withstand this radiation for long enough to capture the necessary information. A new method, known as serial femtosecond crystallography, outruns the radiation-damage problem by using short X-ray laser pulses that radiate a steady stream of small crystals.

Read more about this research from the 29 November issue of Science Express here.

[Image courtesy of Michael Duszenko, University of Tübingen; click the image for more information.]

© 2012 American Association for the Advancement of Science. All Rights Reserved.

Arsenic-Based Compounds as Backup Against Phosphine-Resistant Pests?

Phosphine is a gas that is used to protect global grain reserves, and the emergence of phosphine-resistant pests represents a serious threat to global food security. With that in mind, David Schlipalius at the Department of Agriculture, Fisheries and Forestry in Brisbane, QLD, Australia and colleagues identified mutations that are shared among some phosphine-resistant insects and nematodes, such as the lesser grain borer, the rust-red flour beetle and the common roundworm.

Read more about this research from the 9 November issue of Science here.

[Image courtesy of Nick Valmas; click the image for more information.]

© 2012 American Association for the Advancement of Science. All Rights Reserved.

© 2014 American Association for the Advancement of Science. All Rights Reserved.