Ribosomes, the cell's protein factories, have been tough targets for researchers aiming to see them close up. Now, for the first time on the atomic scale, scientists know what most of the ribosome looks like.
A new map reveals most of the structures of the two RNA molecules and 31 proteins that make up the larger of the two subunits of a bacterial ribosome. The map suggests where and how the ribosome chemically stitches amino acids into a protein.
The new details confirm suspicions that ribosomes' RNA molecules, and not their proteins, make peptides. That result adds to evidence that an RNA-based biochemistry preceded today's DNA-based biology (SN: 8/10/96, p. 93). The results also will help researchers tease out further detai