Structural Biochemistry/Roger D. Kornberg
Roger David Kornberg was born in April 24th, 1947, and was the Nobel Prize winner of Chemistry in 2006 for his research in eukaryotic transcription.
Transcription is part of the Central Dogma in which DNA is transcribed into RNA and then translated into proteins. In DNA transcription, mRNA is transcribed by an enzyme called RNA polymerase II with the help of other proteins. In Kornberg’s research at Stanford University, yeast was used to determine the three-dimensional structure of a protein cluster of RNA polymerase II and other proteins. Identification of transcription machinery, to Kornberg, was necessary in order to further the study of transcriptional regulation. In addition, yeast was used because it was a unicellular organism that had the same RNA polymerase II system as mammalian systems. Kornberg first accomplished this by creating a technique to form a two-dimensional protein crystal on lipid membranes to produce a low resolution image of the RNA polymerase II. Later, he was able to use this technique to yield larger crystals that could be used in x-ray crystallography to determine the three-dimensional structure of RNA polymerase II on an atomic level. This technique was then applied to find the other accessory proteins that are associated with RNA polymerase II. He then used this information about the proteins to determine the transcription process of yeast by isolating purified forms of certain proteins in transcription. These discoveries in yeast, Kornberg was able to detect an additional protein that transmitted gene regulation signals to the RNA polymerase II that was named “Mediator”. The discovery of the “mediator” was, “a true milestone in the understanding of the transcription process” according to the Nobel Prize committee.