by Benjamin Tran
For decades, Stanford Professor Roger Kornberg in the Department of Structural Biology has used his sophisticated biochemical knowledge and expertise in crystallography of biological molecules to study the molecular basis of eukaryotic transcription. In 2001, Kornberg produced the first pictures of RNA polymerase in action, transcribing DNA into RNA in the cell nucleus. This work earned him the 2006 Nobel Prize in Chemistry.
Kornberg was able to freeze the transcription process by leaving out one of the building blocks of RNA during transcription. When RNA polymerase reached the point where the missing block should be inserted, the transcription process stopped. Using a combination of electron microscopy and X-ray crystallography, Kornberg was then able to determine the crystal structure of RNA polymerase and provide insight into the molecular dynamics of transcription. For the first time, biologists and chemists could actually see a nucleotide binding to RNA polymerase in a precise conformation and observe the subsequent elongation of the RNA strand.
Using this method, Kornberg and colleagues went on to elucidate the workings of DNA enhancers that stimulate the transcription of certain genes. He found that this process is controlled by a protein called mediator that transmits signals to activate and suppress transcription.
Kornberg's work provides an example of the power of using intensive biochemical knowledge to answer fundamental questions. He hopes that his Nobel Prize will be an inspiration for scientists doing fundamental research, students interested in it, and those who support it. ÒOne of the benefits of the Nobel Prize is the light it casts on the pursuit of knowledge for its own sake and the encouragement it gives people irrespective of the possible gains,Ó Kornberg said. ÒWhat's more, it's a testament to governmental institutions and politicians that support this research, knowing that the gains may be in the far future.Ó