2014N1222

1. Gouhara San: Nature #512 No. 7514
The complete structure of the large subunit of the mammalian mitochondrial ribosome
Mitochondrial ribosome is always a hot topic. Until now, many subunits of this complex have been resolved. But nobody resolves the structure of subunit from mammalian. Authors solved this problem by using Cryo-EM instead of traditional X-ray crystalgraphy, since such a large complex might be difficult to be expressed and to be purified, and they finally got a high resolution. Due to a high similarity of this subunit of protein complex from pig to that from human, this structural information might be used to cure of relative disease in the human.

2, Ono San, Science Vol., 346 Issue 6214
page 1377 Ultrastable gold substrates for electron cryomicroscopy
The author used the gold as the substrate instead of the carbon that is extensively used for an observation by Cyro-EM. They found that the sample like 80S ribosome on the grid formed by gold on surface of the substrate is much stable than that on the grad formed by the carbon. Because the motion of particle is reduced, a resolved high resolution by Cyro-EM becomes possible. Although the substrates made from gold is much expensive, the limit of observation is broken due to change of substrate material from carbon to gold.

3, Hirata san, PNAS Vol. 111, No., 30
Predictive energy landscapes for folding a-helical transmembrane proteins
Following increased numbers of membrane protein, authors simulated these known structure of membrane protein based on associative memory, water-mediated, structure and energy, and set up a model, names as AWSEM. The basic principal is based on energy landscapes of transmembrane proteins dependent on 2nd level information and topology of protein, but not based on alignment with the similar protein structure. They found simulated structure of membrane protein is almost same to the derived from the experimentally determined structure. Thus, when structure alignment of membrane protein is not available because no similar structure was resolved, this method can be well applied to give simulated structure with a high accuracy.

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