Engineering protein assemblies with allosteric control via monomer fold-switching

• Published in: Nature communications Vol. 10; no. 1; pp. 5703 - 13
• Main Authors: Campos, Luis A., Sharma, Rajendra, Alvira, Sara, Ruiz, Federico M., Ibarra-Molero, Beatriz, Sadqi, Mourad, Alfonso, Carlos, Rivas, Germán, Sanchez-Ruiz, Jose M., Romero Garrido, Antonio, Valpuesta, José M., Muñoz, Victor
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 13.12.2019; Nature Publishing Group; Nature Portfolio
• Subjects: 101/28; 101/6; 119/118; 631/1647/338; 631/1647/350; 631/45/470; 631/45/535; 631/57/2266; 82/16; Allosteric properties; Allosteric Regulation; Assemblies; Cloning, Molecular; Humanities and Social Sciences; Macromolecules; Metamorphosis; Molecular Docking Simulation; Molecular Dynamics Simulation; multidisciplinary; Mutation; Protein engineering; Protein Engineering - methods; Protein Folding; Protein Multimerization - genetics; Protein Structure, Secondary - genetics; Proteins; Proteins - genetics; Proteins - isolation & purification; Proteins - metabolism; Recombinant Proteins - genetics; Recombinant Proteins - isolation & purification; Recombinant Proteins - metabolism; Science; Science (multidisciplinary); Serine Proteases - metabolism; Serine Proteinase Inhibitors - genetics; Serine Proteinase Inhibitors - isolation & purification; Serine Proteinase Inhibitors - metabolism
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-019-13686-1

The macromolecular machines of life use allosteric control to self-assemble, dissociate and change shape in response to signals. Despite enormous interest, the design of nanoscale allosteric assemblies has proven tremendously challenging. Here we present a proof of concept of allosteric assembly in which an engineered fold switch on the protein monomer triggers or blocks assembly. Our design is based on the hyper-stable, naturally monomeric protein CI2, a paradigm of simple two-state folding, and the toroidal arrangement with 6-fold symmetry that it only adopts in crystalline form. We engineer CI2 to enable a switch between the native and an alternate, latent fold that self-assembles onto hexagonal toroidal particles by exposing a favorable inter-monomer interface. The assembly is controlled on demand via the competing effects of temperature and a designed short peptide. These findings unveil a remarkable potential for structural metamorphosis in proteins and demonstrate key principles for engineering protein-based nanomachinery. The design of protein assemblies is a major thrust for biomolecular engineering and nanobiotechnology. Here the authors demonstrate a general mechanism for designing allosteric macromolecular assemblies and showcase a proof of concept for engineered allosteric protein assembly.