Nobel Prize for chemistry of life; venkatraman ramakrishnan

The 2009 chemistry Nobel Prize has been awarded to Venkatraman Ramakrishnan, Thomas Steitz and Ada Yonath.

The announcement was made during a press conference at the Royal Swedish Academy of Sciences, during which the three winners were described as "warriors in the struggle of the rising tide of incurable bacterial infections".

Professor Ramakrishnan is based at the Medical Research Council's Molecular Biology Laboratories in Cambridge, UK.

Thomas Steitz is based at Yale University in the US, and Ada Yonath is from the Weizmann Institute in Rehovot, Israel.

The prize is to be shared equally between the three scientists, who all contributed to revealing the ribosome's huge and complex molecular structure in remarkable detail.

Professor David Garner, president of the Royal Society of Chemistry, described the three as "great scientists" and said their work was of "enormous significance".

The prize is awarded for the study of the structure and function of the ribosome - the cell's protein factory.

The ribosome translates genetic code into proteins - which are the building blocks of all living organisms.

It is also the main target of new antibiotics, which combat bacterial strains that have developed resistance to traditional antibiotic drugs.

These new drugs work by blocking the function of ribosomes in bacterial cells, preventing them from making the proteins they need to survive.

This is the 101st chemistry Nobel to be awarded since 1901, and Professor Yonath is only the fourth woman to win. She joins an illustrious list of female chemists that includes Marie Curie, who also won the physics award.

During the press conference, Professor Yonath said: "It's above and beyond my dreams and I am very thankful."

President of the American Chemical Society Thomas Lane told the BBC that the award was "a wonderful example of leaders in their disciplines - people from around the world - working towards a common goal and being able to achieve it.

"It shows that as scientists we don't just sit in our dark labs, we come together and share our research."

He added: "With advances in analytical chemistry, computer science and imaging, we now have a valid window into these cellular structures.

"This gives other scientists the knowledge to create new drugs, and new materials to combat disease."

Working together

These scientists and their colleagues have helped build a 3D structure of the ribosome.

In doing so, they solved an important part of the the problem posed by Francis Crick and James Watson when they discovered the twisted double helix DNA structure - how does this code become a living thing?

The work laid foundations for the design of new antibiotics

DNA is made available to the ribosome by "transcription" of genes into chunks of messenger RNA.

In the ribosome, these are read and translated into the various amino acid sequences that make up an organism's proteins.

By looking closely at its structure, scientists are able to study how this translation process works.

The work is based on a technique called x-ray crystallography - where protein molecules are removed from cells, purified and made into crystals that can be examined using x-rays.

Addressing the Nobel press conference by telephone, Professor Yonath said that modern techniques were allowing scientists to look at the structures on the atomic scale - individual bond after individual bond.