Roger David Kornberg (born April 24,[3] 1947) is an American biochemist and professor of structural biology at Stanford University School of Medicine.

Kornberg was awarded the Nobel Prize in Chemistry in 2006 for his studies of the process by which genetic information from DNA is copied to RNA, "the molecular basis of eukaryotic transcription.

While a graduate student working with Harden McConnell at Stanford in the late 1960s, he discovered the "flip-flop" and lateral diffusion of phospholipids in bilayer membranes.

[17] Using this system, Kornberg made the major discovery that transmission of gene regulatory signals to the RNA polymerase machinery is accomplished by an additional protein complex that they dubbed Mediator.

[18] As noted by the Nobel Prize committee, "the great complexity of eukaryotic organisms is actually enabled by the fine interplay between tissue-specific substances, enhancers in the DNA and Mediator.

"[19] At the same time as Kornberg was pursuing these biochemical studies of the transcription process, he devoted two decades to the development of methods to visualize the atomic structure of RNA polymerase and its associated protein components.