Enzymes are a picky lot. Of the many thousands of molecules drifting through their environment, most enzymes will react with only one-its preferred substrate, or target.

The secret to that specificity is buried in the nooks and crannies of an enzyme's active site. The amino acids lining this pocket both help an enzyme bind to its substrate and catalyze a chemical reaction. The positions of these amino acids, in turn, are controlled by genes.

"We want to figure out how to discover the few most important gene mutations that will change enzyme specificity," says Jack Kirsch, Professor of the Graduate School Division of Biochemistry and Molecular Biology. "But we don't know which changes will give it the new activity."

»sciencematters.berkeley.edu/arch···ory3.php