NIRENBERG, MARSHALL WARREN

born April 10, 1927, New York, N.Y., U.S. American biochemist and corecipient, with Robert William Holley and Har Gobind Khorana, of the 1968 Nobel Prize for Physiology or Medicine. He was noted for his role in deciphering the genetic code. He demonstrated that, with the exception of nonsense codons, each possible triplet (called a codon) of four different kinds of nitrogen-containing bases found in deoxyribonucleic acid (DNA) and, in some viruses, in ribonucleic acid (RNA) ultimately causes the incorporation of a specific amino acid into a cell protein. Nirenberg received his Ph.D. from the University of Michigan in 1957 and that year joined the staff of the National Institutes of Health in Bethesda, Maryland. His research earned him the National Medal of Science in 1965. His work and that of Holley and Khorana helped to show how genetic instructions in the cell nucleus control the composition of proteins.