Marshall Warren Nirenberg
Marshall Warren Nirenberg (born April 10, 1927) was a U.S. biochemist and geneticist. He shared a Nobel Prize in Physiology or Medicine in 1968 with Har Gobind Khorana and Robert W. Holley for describing the genetic code and how it operates in protein synthesis.
Research
By 1959, experiments by Oswald Avery, Francis Crick, James D. Watson, and others had shown DNA to be the molecule of genetic information. It was not known, however, how DNA was replicated, how DNA directed the expression of protiens, or what role RNA had in these processes. Nirenberg teamed up with Heinrich J. Matthaei at the National Institutes of Health to answer these questions. They produced RNA comprised solely of uracil, a nucleotide that only occurs in RNA. They then injected this synthetic poly-uracil RNA into the bacterium Escherichia coli. The bacteria produced a novel protien, comprised only of a chain of the amino acid phenylalanine. They realized that they had found the genetic code for phenylalanine: UUU (three uracil bases in a row) on RNA. This was the first step in deciphering the codons of the genetic code and the first demonstration of messenger RNA (see Nirenberg and Matthaei experiment).
Nirenberg received great scientific attention for these experiments. Within a few years, his research team had performed similar experiments and found that three-base repeats of adenosine (AAA) produced the amino acid lysine, cytosine repeats (CCC) produced proline and guanine repeats (GGG) produced nothing at all. The next breakthrough came when Phillip Leder, a postdoctoral researcher in Nirenberg's lab, developed a filtration method for determining the order of nucleotides on a piece of RNA (see Nirenberg and Leder experiment). This greatly sped up the assignment of three-base codons to amino acids and by 1966, Nirenberg announced that he had deciphered all sixty-four RNA codons for all twenty amino acids.
Nirenberg's later research focused on neuroscience, neural development, and the homeobox genes.
Biography
Nirenberg was born in New York City, the son of Harry and Minerva Nirenberg. He developed rheumatic fever as a boy, so the family moved to Orlando, Florida to take advantage of the subtropical climate. He developed an early interest in biology. In 1948 he received his B.S. degree, and in 1952, a master's degree in zoology from the University of Florida at Gainesville. His dissertation for the Master's thesis was an ecological and taxonomic study of caddis flies (Trichoptera). He received his Ph.D. in biochemistry from the University of Michigan, Ann Arbor in 1957.
He began his postdoctoral work at the National Institutes of Health (NIH) in 1957 as a fellow of the American Cancer Society. In 1960 became a research biochemist at the NIH. In 1959 he began to study the steps that relate DNA, RNA and protein. Nirenberg's groundbreaking experiments advanced him to become the head of the Section of Biochemical Genetics in 1962. He was married in 1961 to Perola Zaltzman, a chemist from the University of Brazil, Rio de Janeiro.