A protein consists of a chain of different amino acids in a specific order, which determines its three-dimensional structure. A remarkably simple protein structure is that of so-called coiled coils. Their amino acid sequence follows a specific repetitive pattern that causes two or more chains of amino acids to form so-called α-helices, which are in turn wound around each other like the strands of a rope. Because of their regular structure, coiled coils are so well understood, that their atomic structure can usually be predicted with high accuracy.
Scientists around Prof. Dr. Andrei Lupas, Director of the Department for Protein Evolution at the Max Planck Institute for Developmental Biology, now discovered a novel protein fiber structure based on classical coiled coils: in the so called α/β coiled coil, the individual α-helices are disrupted by structural elements that the researchers termed β-layers. They showed that the formation of these elements can be brought about by the specific insertion of certain numbers of amino acids into the regular coiled-coil sequence pattern.
The researchers came across this discovery while studying the structure of a class of fibrous proteins that are used by bacteria and viruses to adhere to their hosts. Therein, β-layers serve as universal connecters between segments of different structure. As such, they facilitate the rapid evolutionary adaptation of these surface proteins.Department website
eLife 2016;10.7554/eLife.11861; DOI: dx.doi.org/10.7554/eLife.11861