Enzyme engineering is undergoing the most profound and exciting transformation in its history (1). It promises unprecedented expansion in the scope and applications of modified or improved enzymes with desired physical and catalytic properties. Two complementary strategies are currently available: rational redesign (2-5) and directed evolution (6,7). Although both approaches have met with great...

The stunning array of features and functions exhibited by proteins in nature should convince most scientists of the power of evolutionary design processes. Natural selection acting on populations over long periods of time has generated a vast number of proteins ideally suited to their biological functions. When we try to recruit these remarkable molecular machines for new taskssfrom serving as ...

Polymerases evolved in nature to synthesize DNA and RNA, and they underlie the storage and flow of genetic information in all cells. The availability of these enzymes for use at the bench has driven a revolution in biotechnology and medicinal research; however, polymerases did not evolve to function efficiently under the conditions required for some applications and their high substrate fidelit...