Which types of amino acid interfaces can support TMD-TMD interaction?
Interactions between transmembrane domains (TMDs) rely on helix/helix interfaces built from specific amino acid motifs. It is currently unclear how many different motifs exist and which types of physical forces they employ.
One approach to identify novel interfacial motifs is to generate libraries of TMDs with random primary structure and use a selection method in model organisms such as Escherichia coli, to select self-interacting sequences. Selected TMDs with strong affinity can then be characterized by scanning mutagenesis to identify novel interfacial motifs that facilitate the TMD-TMD interaction.