Genetic approaches to biochemical questions: insights into the functional requirements of proline 185 in the active site of human galactose-1-phosphate uridylyltransferase.

Saturating random mutagenesis at a given position within a polypeptide sequence can provide powerful insights into the functional requirements of the position. By coupling this genetic methodology with expression of human proteins in yeast, we and others have begun to ask pointed and important questions about the structure-function relationships of proteins associated with human genetic disease.