Trio wins chemistry Nobel for solving ribosome riddle

By Mia Shanley

STOCKHOLM (Reuters) - Three scientists who produced atom-by-atom maps of the mysterious, life-giving ribosome won the Nobel chemistry prize on Wednesday for a breakthrough that has allowed researchers to develop powerful new antibiotics.

While DNA molecules contain the blueprint for life inside each cell of every organism, it is the ribosome that translates that information into life.

Israeli Ada Yonath and Americans Venkatraman Ramakrishnan and Thomas Steitz shared the 10 million Swedish crown ($1.4 million) prize for showing how the ribosome, a kind of protein factory, operates at the atomic level.

"As ribosomes are crucial to life, they are also a major target for new antibiotics," the Nobel Committee for Chemistry at the Royal Swedish Academy of Sciences said in a statement.

The academy said many of today's antibiotics cure various diseases by blocking the function of bacterial ribosomes.

Yonath, a professor at the Weizmann Institute of Science in Israel, told a news conference by telephone that she was elated to receive the award: "It is above and beyond my dreams."

A method known as X-ray crystallography was used to pinpoint each of the hundreds of thousands of atoms in a ribosome.

The technique involves aiming X-rays at a crystal. The rays scatter when they hit atoms and by looking at how they spread out, scientists can determine where atoms are positioned.

Yonath made the initial breakthrough at the end of the 1970s when she first tried the method on the ribosome -- a feat most considered impossible.

LIFE IN THE DEAD SEA

Yonath started by taking a micro-organism found in the nearby Dead Sea and crystallizing its ribosomes. She did this by freezing them at nearly minus 200 degrees Celsius.

Jeremy Berg, director of the U.S. National Institute of General Medical Sciences which funded the work of all three researchers, said he was amazed at how intrepid Yonath was.

"I remember at the time being just completely stunned that she was somewhere between brave enough and crazy enough because it was way, way, way beyond the technology available at that point," he told Reuters.

But it would take another 20 years before a full map could be made. During that time, two others joined the race: Yale University's Steitz and Indian-born Ramakrishnan of the MRC Laboratory of Molecular Biology in Britain.

In 1998, Steitz published the first crystal structure of a large part of a ribosome, something that looked like a dim photograph. The three scientists reached the finish line almost simultaneously in 2000, publishing crystal structures that were sharply enough defined to locate atoms.