ABSTRACT
Enzymes, the catalysts of life, are used by living cells and organisms to sustain their development. Consequently, natural evolution has only selected those catalysts that are useful for the growth of cells in their natural environment. In the last decade, several strategies have been envisaged to modify natural enzymes in order to widen their range of applications. Engineering by rational design, preferentially guided by molecular modelling, has sometimes led to remarkable results (1). However, this approach remains quite challenging. Indeed, the number of contributions reporting successful experiments has not exploded in the last years, and it is difficult to
Figure 1 Construction of a phage-enzyme by cloning into gene 3 of a filamentous phage between sequences encoding the signal pep tide and the mature protein. A tetracyclin resistance gene allows in vivo selection of E. coli cells infected by the phage.
