IDENTIFICATION OF (POLY)PEPTIDE-(POLY)PEPTIDE INTERACTIONS

A method for identifying (poly)peptide-(poly)peptide interactions comprises transforming a cell with a first expression vector encoding a first fusion protein between a first (poly)peptide and a first inactive part of Cre recombinase and a second expression vector encoding a second fusion protein between a second (poly)peptide and a second inactive part of Cre recombinase and comprising a selectable marker not operatively linked to any promoter Interaction between the first and second (poly)peptides of two fusion proteins induces activation of the Cre recombinase and in trans recombination of the expression vectors into a first recombined vector and in cis recombination of the first recombined vector to bring the selectable marker operatively linked to a promoter, wherein the expression of the selectable marker indicates interaction between the first and second (poly)peptides in the cell. The invention also relates to a kit and expression vector that can be used in the method.