Stuff of life wins trio chem Nobel

STOCKHOLM: Three scientists who produced atom-by-atom maps of the mysterious, life-giving ribosome won the Nobel Prize for chemistry yesterday, a breakthrough that has been vital for the development of 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 crowns ($1.4 million) prize for showing how the ribosome, which produces protein, functions at the atomic level.

The Nobel committee said the trio's contribution had been in X-ray crystallography that had generated 3D models, helping to showing the ribosome's individual atomic structure.

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

These models are now being harnessed by scientists in the quest for new microbe-killing drugs, "directly assisting the saving of lives and decreasing humanity's suffering," the jury said.

"Many of today's antibiotics cure various diseases by blocking the function of bacterial ribosomes," it said. "Without functional ribosomes, bacteria cannot survive. This is why ribosomes are such an important target for new antibiotics."

Yonath told a news conference by telephone that the award "is above and beyond my dreams".

At 70, she is just the fourth woman to win the Nobel Chemistry Prize. "I was in my daughter's home in Israel and the first reaction was overwhelming happiness. She is so proud, so this made me even happier," Yonath told Swedish television moments later.

All three scientists used a method called X-ray crystallography to map the position for each of the hundreds of thousands of atoms that make up the ribosome.

Yonath made an initial breakthrough at the end of the 1970s when she first tried to generate X-ray crystallographic structures of the ribosome, a feat most considered impossible.

The method involves aiming X-rays towards a crystal, which then scatter when they hit atoms. By looking at how the rays spread out, scientists can determine how atoms are positioned.

Jeremy Berg, director of the US National Institute of General Medical Sciences, which funded all three scientists, 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," Berg said.

Working with a micro-organism found in the nearby Dead Sea, Yonath cyrstallized ribosomes by freezing them at nearly minus 200 degrees Celsius.

It would take another 20 years before a full map could be made, during which time Steitz and Ramakrishnan joined the race.

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, publishing crystal structures in 2000 that were sharply defined enough to locate atoms.

The academy said all three had generated three-dimensional models showing how different antibiotics bind to the ribosome.

Indian-born Ramakrishnan is a senior scientist at MRC Laboratory of Molecular Biology at Cambridge, England. Steitz is at Yale University and Yonath works at the Weizmann Institute of Science in Israel.

Reuters-AFP

(China Daily 10/08/2009 page8)