α-helical coiled coils are ubiquitous elements of protein structure, formed by two or more helices wound in a superhelical array . Though generally of fibrous appearance, coiled coils become progressively barrel-like as their number of constituent helices increases and they start enclosing a central, solvent-filled channel. Due to their intrinsic stability, coiled coils are widely used in biology to provide mechanically and chemically resilient fibers, oligomerization platforms, scaffolds for protein complex assembly, stalks and arms for molecular machines , levers for membrane fusion and channels for solute transport.
We have been interested in coiled coils for a long time, studying their properties  and classifying their structural diversity  [Figure 1]. Uniquely among proteins, their tertiary structure has been fully parametrized, making them particularly attractive for protein design , protein structure prediction [5,6] and quantitative analysis  projects.
Over the years we have applied our theoretical insights to a wide range of proteins; our main current focus in this area is on bacterial Trimeric Autotransporter Adhesins (TAAs)  and transmembrane receptors . We have also started to design new coiled coils with unusual core residues and odd periodicities.