The Cell’s Computer--Molecular Structure of the Ribosome is Solved

In another major scientific milestone, researchers at Yale University under the guidance of Dr. Thomas A. Steitz, have resolved the three-dimensional crystal structure of the large ribosomal subunit, one of the cell's most sophisticated organelles, to 2.4 Å.

The ribosome is one of the most crucial components of the cell. The large ribosomal subunit catalyzes peptide bond formation and binds initiation, termination and elongation factors. The bacterium that was used in these studies is Haloarcula marismortui, which is found in the Dead Sea in Israel. The detailed picture of the ribosome includes 2833 of the subunit's 3045 nucleotides and 27 of its 31 proteins and shows the positions of approximately 100,000 atoms. In a related study, researchers have found that the structure of the ribosome consists mostly of RNA rather than proteins. This means that the ribosome is actually a ribozyme, and that proteins are made in the ribosome, by a large complex of proteins and RNA, in reactions that are catalyzed by ribosomal RNA (rRNA). This fact is of enormous significance in that it confirms theories about the significance of RNA in giving birth to DNA, and consequently, the protein-based world.

The nano-molecular structure of the ribosome has long fascinated scientists. With the emphasis in biology shifting dramatically towards understanding biological systems as information processing systems, the ribosome has received renewed attention. The ribosome, in fact, bears an uncanny resemblance to the basic model of computation that underlies all modern computers, known as the Turing model.