Yanofsky, Charles (1925- )

US geneticist who demonstrated a linear correspondence between the sequence of bases along the DNA of a gene and the amino acid sequence of the gene's protein product.

He examined numerous strains of the bacterium Escherichia coli that carry mutations in the gene for tryptophan synthetase (the enzyme that catalyses the final step in the production of the amino acid tryptophan). The positions of the mutations in the tryptophan synthetase gene were mapped by measuring frequencies of recombination (the ‘shuffling’ of genetic material that increases variation in the offspring). The position and nature of the change in each mutant tryptophan synthetase protein was then identified. The order of the mutations in the gene proved to correspond to the amino acid sequence of the gene's protein product. These results were the first proof that genes and their polypeptide products correspond.

Yanofsky was born in New York City and studied biology at New York City College and Yale University. He has been professor of biology at Stanford University in California since 1961.