Thomas A. Steitz, PhD, Sterling Professor of Molecular Biophysics and Biochemistry at Yale and one of three winners of the 2009 Nobel Prize in Chemistry, died Oct. 9 after a battle with pancreatic cancer. Steitz was 78.

Steitz, who was also professor of chemistry at Yale and a Howard Hughes Medical Institute investigator, was recognized by the Royal Swedish Academy for his work describing the structure and function of the ribosome, the cellular protein-making factory essential to life.

“Tom demonstrated to the world the importance of fundamental and cross-disciplinary research,” said President Peter Salovey, PhD ’86. “The Yale community will remember him for his immeasurable contributions to science and education.”

The instruction manual for the creation of proteins is DNA, but the ribosome is the machine that translates the encoded information to turn it into proteins. Steitz’s work elucidated the structure and function of the ribosome, an enormously complex ensemble of numerous protein and RNA components.

“I think we were amazed at each stage at the overwhelming complexity of the RNA folding in the ribosome,” Steitz said in an interview. “But I think the most surprising observation was that the proteins were embedded among the RNA helices, penetrating into the interior of the ribosome like tentacles.”

Working with Yale colleagues Peter Moore, PhD, professor emeritus of chemistry, and Donald Engelman, PhD, Eugene Higgins Professor of Molecular Biophysics and Biochemistry, Steitz helped establish a structural biology center at Yale. By 2000, their use of high-resolution X-ray crystallography enabled the team to resolve the atomic structure of all components of the ribosome.

“He was a very generous and wonderful colleague and had a great ability to find scientific problems to solve,” Moore said. “Many scientists work on one problem all their lives, but he solved many. He was the most accomplished structural biologist of his generation.

“Professor Steitz deeply valued his relationships with his colleagues, placing great importance on the face-to-face interactions and discussions that helped shape his work,” said Robert J. Alpern, MD, dean and Ensign Professor of Medicine. “His enjoyment of that work was evident, and he will long be remembered as a role model and inspiration to the scores of individuals he mentored.”

Steitz received many awards, including the Gairdner International Award in 2007, the year after his wife of 52 years, Joan A. Steitz, PhD, Sterling Professor of Molecular Biophysics and Biochemistry, won the prestigious award.

Steitz’s death came two weeks after Joan Steitz received the Lasker~Koshland Award for Special Achievement in Medical Science.