Why is X-ray crystallography important for biology?
X-ray crystallography is essential because it reveals atomic-level details of biological molecules, and the beauty of crystallography is that it reveals the truth. Without it, we would be guessing at how proteins and nucleic acids function. For the ribosome, we had to grow crystals of this huge complex, collect diffraction data at synchrotrons, and solve the phase problem using heavy atom derivatives. The resulting electron density maps allowed us to build models of every atom. This method is not just descriptive—it generates testable hypotheses. For instance, seeing how the ribosome distinguishes correct from incorrect tRNAs led to experiments confirming the role of conformational changes. You can't just speculate; you have to do the experiment, and crystallography provides the structural foundation for that.
Ask Venkatraman Ramakrishnan the follow-up →