GETTING MORE FROM THE 2-HYBRID SYSTEM - N-TERMINAL FUSIONS TO LEXA ARE EFFICIENT AND SENSITIVE BAITS FOR 2-HYBRID STUDIES

Two-hybrid methods detect interactions between two proteins fused at t he C-termini of, respectively, a DNA-binding domain and the activation domain of a transcriptional activator. Thus the N-terminus of none of these proteins is available for interaction. We have tested whether a bait protein with a reverted polarity (i.e. N-bait-LexA-C) is suitabl e for two-hybrid interaction. We show that such constructs give a spec ific interaction signal, and document two cases where the sensitivity is dramatically increased. Such constructs might lead to the identific ation of partners missed during classical two-hybrid screens.