The structure of the small ribosomal subunit has been determinded at the highest resolution ever achieved by a team of Weizmann Institute and Max Planck Society scientists. Their findings, aided by the unique utilization of functional probes, have unraveled key ribosomal features including the site where protein biosynthesis begins (PNAS 7 December 1999). The study, made possible through a novel experimental strategy, will boost efforts to decipher the structure and function of the ribosome - the cell's protein factory.
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 it's darker side - the emergence of disease when production goes haywire. This explains why ribosomes have 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. The beam diffracted from crystals of natural and slightly modified materials creates a pattern that coupled with sophisticated computational analysis demonstrates the crystal's components and the nature of their spatial interactions. However, the ribosome, a notoriously unstable giant nucleoprotein 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 a
Contact: Ada Yonath