Protein-Protein Interactions: Oxidative Bacterial Two Hybrid.

Protein-protein interaction studies are essential to understand how proteins organize themselves into interaction networks and thus influence cellular processes. Protein binding specificity depends on the correct three-dimensional folding of the polypeptide sequences. One of the forces involved in the structuring and stability of proteins is the formation of disulfide bonds. These covalent bonds are formed posttranscriptionally by the oxidation of a pair of cysteine residues and can serve structural, catalytic, or signaling roles. Here, we describe an engineered E. coli adenylate cyclase mutant strain with an oxidative cytoplasm that promotes correct folding of proteins with disulfide bonds. This genetic background expands the set of host strains suitable for studying protein-protein interactions in vivo by the adenylate cyclase two-hybrid approach.