Three scientists will share the Nobel Prize in Chemistry for their studies of the structure and function of ribosomes, which are crucial to life.

The Royal Swedish Academy of Sciences announced Wednesday that Americans Venkatraman Ramakrishnan and Thomas Steitz and Israeli Ada Yonath will be the Nobel chemistry prize laureates.

Based upon the information in DNA, ribosomes produce proteins such as oxygen-transporting haemoglobin, antibodies of the immune system, hormones like insulin, the collagen of the skin and the enzymes that break down sugar.

Ribosomes translate DNA information into the chemistry of all living organisms. They are also a major area of study for the creation of new antibiotics because without functional ribosomes, bacteria cannot survive.

"An understanding of the ribosome's innermost workings is important for a scientific understanding of life," the citation said. "This knowledge can be put to a practical and immediate use; many of today's antibiotics cure various diseases by blocking the function of bacterial ribosomes."

The work of the three scientists has examined what ribosomes look like and how they functions at the atomic level, said the prize's citation. Their work includes 3-D models that show how different antibiotics bind to ribosomes.

Discovery decreases 'humanity's suffering'

"These models are now used by scientists in order to develop new antibiotics, directly assisting the saving of lives and decreasing humanity's suffering," the prize citation said.

Yonath, 70, is the fourth woman to win the Nobel chemistry prize and the first since 1964, when Dorothy Crowfoot Hodgkin of Britain received the award.

"I'm really, really happy," Yonath said. "I thought it was wonderful when the discovery came. It was a series of discoveries.… We still don't know every, everything, but we progressed a lot."

The researchers used a method called X-ray crystallography to pinpoint the positions of the hundreds of thousands of atoms that make up the ribosome.

Their work builds on the Charles Darwin's theory of evolution and, more directly, on the work done by James Watson, Francis Crick and Maurice Wilkins who won the 1962 Nobel Prize in medicine for mapping DNA's double helix, the citation said.

The three will share an award of 10 million kronor ($1.5 million). Each will also receive a diploma and an invitation to the prize ceremonies in Stockholm on Dec. 10, the anniversary of Alfred Nobel's death in 1896.

Indian-born Ramakrishnan, 57, is the senior scientist and group leader at the Structural Studies Division of the MRC Laboratory of Molecular Biology in Cambridge, England.

Steitz, a 69-year-old born in Milwaukee, is a professor of molecular biophysics and biochemistry at Yale University and attached to the Howard Hughes Medical Institute, both in New Haven, Conn.

Yonath is a professor of structural biology at the Weizmann Institute of Science in Rehovot, Israel.

3rd of 6 awards

The prize announcement is the third of six awards focusing on medicine, physics, chemistry, economics, literature and the Peace Prize that will be announced through Oct. 12.

Nobel, the Swede who invented dynamite, established the prizes in his will in the categories of medicine, physics, chemistry, literature and peace. The economics prize is technically not a Nobel but a 1968 creation of Sweden's central bank.

On Tuesday, three scientists, including Canadian Willard S. Boyle, received the Nobel Prize in Physics for discoveries that include the transmission of light in fibres for optical communication and the invention of the charge-coupled device (CCD sensor), which is an imaging semiconductor circuit used as a digital camera's electronic eye.

On Monday, three American scientists shared the Nobel Prize in Medicine for discovering a key mechanism in the genetic operations of cells, an insight that has inspired new lines of research into cancer.

With files from The Associated Press