Imaging of the assembled TET12 reveals tetrahedral topology. Credit: Nature Chemical Biology (2013) doi:10.1038/nchembio.1248 More information: Design of a single-chain polypeptide tetrahedron assembled from coiled-coil segments, Nature Chemical Biology (2013) doi:10.1038/nchembio.1248AbstractProtein structures evolved through a complex interplay of cooperative interactions, and it is still very challenging to design new protein folds de novo. Here we present a strategy to design self-assembling polypeptide nanostructured polyhedra based on modularization using orthogonal dimerizing segments. We designed and experimentally demonstrated the formation of the tetrahedron that self-assembles from a single polypeptide chain comprising 12 concatenated coiled coil–forming segments separated by flexible peptide hinges. The path of the polypeptide chain is guided by a defined order of segments that traverse each of the six edges of the tetrahedron exactly twice, forming coiled-coil dimers with their corresponding partners. The coincidence of the polypeptide termini in the same vertex is demonstrated by reconstituting a split fluorescent protein in the polypeptide with the correct tetrahedral topology. Polypeptides with a deleted or scrambled segment order fail to self-assemble correctly. This design platform provides a foundation for constructing new topological polypeptide folds based on the set of orthogonal interacting polypeptide segments. Citation: Bioengineering team creates self-forming tetrahedron protein (2013, April 29) retrieved 18 August 2019 from https://phys.org/news/2013-04-bioengineering-team-self-forming-tetrahedron-protein.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.