De novo design of a homo-trimeric amantadine-binding protein.
Park, J., Selvaraj, B., McShan, A.C., Boyken, S.E., Wei, K.Y., Oberdorfer, G., DeGrado, W., Sgourakis, N.G., Cuneo, M.J., Myles, D.A., Baker, D.(2019) Elife 8
- PubMed: 31854299 
- DOI: https://doi.org/10.7554/eLife.47839
- Primary Citation of Related Structures:  
6N9H, 6NAF - PubMed Abstract: 
The computational design of a symmetric protein homo-oligomer that binds a symmetry-matched small molecule larger than a metal ion has not yet been achieved. We used de novo protein design to create a homo-trimeric protein that binds the C 3 symmetric small molecule drug amantadine with each protein monomer making identical interactions with each face of the small molecule. Solution NMR data show that the protein has regular three-fold symmetry and undergoes localized structural changes upon ligand binding. A high-resolution X-ray structure reveals a close overall match to the design model with the exception of water molecules in the amantadine binding site not included in the Rosetta design calculations, and a neutron structure provides experimental validation of the computationally designed hydrogen-bond networks. Exploration of approaches to generate a small molecule inducible homo-trimerization system based on the design highlight challenges that must be overcome to computationally design such systems.
Organizational Affiliation: 
Department of Biochemistry, University of Washington, Seattle, United States.