From the announcement:
This year's Nobel Prize in Chemistry awards Venkatraman Ramakrishnan, Thomas A. Steitz and Ada E. Yonath for having showed what the ribosome looks like and how it functions at the atomic level. All three have used a method called X-ray crystallography to map the position for each and every one of the hundreds of thousands of atoms that make up the ribosome.
The ribosome is the molecular machine inside the cell that synthesizes proteins. The instructions for creation of proteins are encoded within the DNA sequence of the genes. In a process known as transcription, the DNA is copied into a similar template called RNA. It is this RNA template that the cell uses to synthesize its proteins. It is the sequence of the A's, U's, C's, and G's that encode the order of the amino acids that make up a protein. The ribosome binds to this RNA template and reads it 3 letters at a time and adds the correct amino acid to the growing protein chain. This process is known as translation.
OK, so there have been thousands of protein structures solved since the 1960s. What's the big deal, you ask? The ribosome is a HUGE complex. Ribosomes from bacteria and higher organisms are slightly different in composition, but they contain just under 100 proteins! But that's not all, the ribosome also has a signficant RNA component as well made up of as many as about 5000 nucleotide bases (the letters). These structures represent one of the largest biological molecule structures solved today.
However, the award is not about the size. From a biochemistry perspective, perhaps the most interesting thing about the ribosome structure is that it revealed that there were no proteins near the site where the growing protein chain is made - this suggests that it is the RNA component of the ribosome that is responsible for catalyzing the chemical reaction that creates the protein. This is unlike almost all other chemical reactions in the cell which are carried out by proteins. From a practical perspective, there are differences between the ribosome of bacteria and that of higher organisms. Given the essential function of the ribosome, this makes it an attractive target for antibiotics. Indeed many antibiotics target bacterial ribosomes. Having the structure of the ribosome will allow scientists to develop novel antibiotics which is vital in this day of increasing antibiotic resistance.
You can view images of the ribosome and some of it's components here.
Yale Daily News (Steitz).
MRC Lab Cambridge (Ramakrishnan).
Jerusalem Post (Yonath).
Of note, Ada Yonath is the first woman to win the Nobel Prize in chemistry since 1964 and only the fourth ever (from the Jerusalem Post link above).
Congratulations to Ramakrishnan, Steitz, and Yonath!