FACTBOX: Nobel chemistry prize - Who are the winners?

(Reuters) - Venkatraman Ramakrishnan, Thomas A. Steitz and Ada E. Yonath shared the 2009 Nobel prize for chemistry for studies of the structure and function of the ribosome.

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

Here are some details about the winners:

* VENKATRAMAN RAMAKRISHNAN:

-- Born in 1952 in Chidambaram, Tamil Nadu, India, he is a U.S. citizen.

-- Gained a PhD in Physics in 1976 from Ohio University.

-- He has been since 1999 a senior scientist and group leader at Structural Studies Division, MRC Laboratory of Molecular Biology, at Cambridge and is a Fellow at Trinity college in Cambridge.

-- Ramakrishnan's crystal structures of the ribosome's small subunit have been crucial for the understanding of how the ribosome achieves its precision. He identified something that could be described as a molecular ruler. Using the ruler twice, the ribosome double-checks that everything is correct.

* THOMAS A. STEITZ:

-- Steitz, born in Milwaukee, Wisconsin in 1940, is the Sterling Professor of Molecular Biophysics and Biochemistry and a Howard Hughes Medical Institute Investigator at Yale University.

-- He received his BA degree in chemistry from Lawrence College in Appleton, Wisconsin in 1962, and a PhD degree in molecular biology and biochemistry from Harvard, with William Lipscomb in 1966.

-- After a year of postdoctoral work in Harvard, he worked in the Medical Research Council Laboratory of Molecular Biology in Cambridge with Dr. David Blow, before joining Yale University.

-- His research has focused on using protein and nucleic acid X-ray crystallography to establish the structural basis of enzyme mechanisms and of protein-nucleic acid interactions in the cell.

-- His structural work on the ribosome and other enzymes involved in DNA replication, translation and transcription, have provided insight into the pathways involved in information transfer and genome stability in the cell.

-- The Steitz lab's work on antibiotics that target the large ribosomal subunit may also help provide the basis for design of new antibiotics effective against antibiotic resistant microorganisms.

* ADA E. YONATH: