Genetic approaches to protein structure and function: point mutations as modifiers of protein function

In this review, I summarize data in the biological literature which underscore the utility of a genetic approach to protein structure/function problems, with emphasis on binding phenomena, particularly of cytokine and growth factor/receptor interactions. Useful parallels or contrasts to chemical ligand/receptor systems and DNA binding protein interactions are examined where they simplify the analysis of protein ligand/receptor interactions. This approach was prompted by the fact that purely rational approaches, based on resolution of the three dimensional structure of proteins, are limited because such data is available for fewer than 3% of the 17,000 proteins for which the amino acid sequence has been deduced by molecular biology techniques.