John Buchanan (biologist)

John Machlin Buchanan (September 29, 1917 – June 25, 2007) was an American professor of biochemistry at the Massachusetts Institute of Technology. He arrived at MIT in 1953 and retired in 1988 after a distinguished career in which he was elected a fellow of the American Academy of Arts and Sciences and the National Academy of Sciences. He played a key role in the development of MIT's Department of Biology as a major force in biochemistry research and was himself a prominent researcher of purine biosynthesis. He died in 2007 at age 89.