A method for the selection of catalytic activity using phage display and proximity coupling.

Phage display has been used extensively for the selection of proteins with binding sites for ligands. Here, as illustrated with the example of DNA polymerase, the use of phage display for selection according to catalytic activity is described. Active enzymes are selected by binding of the reaction product P (see the scheme) cross-linked in the proximity of the enzyme E that catalyzed the reaction with the substrate S.