STOCKHOLM - American Roger Kornberg has won the 2006 Nobel prize for chemistry for describing the essential process of gene copying in cells, research that can give insight into illnesses such as cancer and heart disease.

The work of Stanford University's Kornberg, 59, has "a fundamental medical importance", the Swedish Academy of Sciences said as it announced the award, worth 10 million Swedish crowns ($2.06 million).

"If transcription stops, genetic information is no longer transferred into the different parts of the body. Since these are then no longer renewed, the organism dies within a few days," the Academy said.

Disturbances in transcription contribute to many human illnesses, such as cancer, heart disease and various kinds of inflammation, it added. Poisonous toadstools kill by interrupting the process.

Understanding transcription is also important for the development of various therapeutic applications of stem cells, the Academy said.

Kornberg was the first to create pictures showing transcription in action. His depictions were so incredibly detailed that separate atoms could be distinguished.