NEW YORK - December 7, 1999 -- A team of Weizmann Institute and Max-Planck Society scientists has determined the structure of the small ribosomal subunit at the highest resolution ever achieved, including the site where protein biosynthesis begins.
Ribosomes, the universal cellular organelles responsible for protein production, are essential to life. Receiving genetically encoded instructions from the cell nucleus, the ribosomal factory churns out proteins - the body's primary component and the basis of all enzymatic reactions. Understanding protein biosynthesis is therefore the gateway to grasping life itself, and its darker side - the emergence of disease - when production goes haywire.
The importance of the ribosome explains why it has been the target of numerous biochemical, biophysical, and genetic studies. However, throughout nearly four decades of research, these pivotal biological units have stubbornly "resisted" scientific attempts to reveal their detailed functional design.
In order to examine microscopic structures scientists expose crystals of the material in question to high intensity x-ray beams - a method known as x-ray crystallography. However, the ribosome, a notoriously unstable giant protein complex, represents a daunting crystallographic challenge. To further complicate matters, it also lacks the internal symmetry and repetitions that eased the way to understanding the structure of other biological entities, such as viruses.
Nevertheless, using novel crystallographic techniques, Professor Ada Yonath of Weizmann's Department of Structural Biology and the Max-Planck Research Units for Ribosomal Structure in Hamburg and Berlin, has now overcome this obstacle. Her study, due to appear in the December issue of the Proceedings of the National Academy of Sciences (PNAS), introduces an electron density map of the small ribosomal subunit from bacterium Thermus thermophilus.
The uniqueness of Yonath's approach lies in phasing
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Contact: Jeffrey J. Sussman, Assist. V.P., Communications
jeffrey@acwis.org
212-779-2500ext. 121
American Committee for the Weizmann Institute of Science
6-Dec-1999