Discovering and designing multistate protein assemblies

Quasisymmetric protein capsids can switch assembly states, transitioning into micron-scale 2D arrays in response to temperature using a single designed sequence.

• Why it matters: Evolved assemblies use multiple weak interfaces and non-symmetric architectures, but designed systems have lacked large-scale structural rearrangements between states.
• What they did: The authors program multiple self-assembling interfaces onto rigid oligomers and use multistate design with ensemble predictions to create alternative interface modes.
• The result: Identical amino acid sequences form distinct configurations depending on assembly pathway and environmental conditions, enabling temperature-triggered capsid-to-2D-array switching.