Navigating the structural landscape of de novo α-helical bundles

Rhys, G. G., Wood, C. W., Beesley, J. L., Zaccai, N. R., Burton, A. J., Brady, R. L., Thomson, A. R. and Woolfson, D. N. (2019) Navigating the structural landscape of de novo α-helical bundles. Journal of the American Chemical Society, 141(22), pp. 8787-8797. (doi: 10.1021/jacs.8b13354) (PMID:31066556)

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Abstract

The association of amphipathic α helices in water leads to α-helical-bundle protein structures. However, the driving force for this—the hydrophobic effect—is not specific and does not define the number or the orientation of helices in the associated state. Rather, this is achieved through deeper sequence-to-structure relationships, which are increasingly being discerned. For example, for one structurally extreme but nevertheless ubiquitous class of bundle—the α-helical coiled coils—relationships have been established that discriminate between all-parallel dimers, trimers, and tetramers. Association states above this are known, as are antiparallel and mixed arrangements of the helices. However, these alternative states are less well understood. Here, we describe a synthetic-peptide system that switches between parallel hexamers and various up–down–up–down tetramers in response to single-amino-acid changes and solution conditions. The main accessible states of each peptide variant are characterized fully in solution and, in most cases, to high resolution with X-ray crystal structures. Analysis and inspection of these structures helps rationalize the different states formed. This navigation of the structural landscape of α-helical coiled coils above the dimers and trimers that dominate in nature has allowed us to design rationally a well-defined and hyperstable antiparallel coiled-coil tetramer (apCC-Tet). This robust de novo protein provides another scaffold for further structural and functional designs in protein engineering and synthetic biology.

Item Type:Articles
Additional Information:G.G.R., C.W.W., J.L.B., A.R.T., A.J.B., and DNW are supported by a European Research Council Advanced Grant to DNW (340764). G.G.R. and A.J.B. thank the Bristol Chemical Synthesis Centre for Doctoral Training funded by the Engineering and Physical Sciences Research Council (EP/ G036764/1). C.W.W. and D.N.W. thank the Biotechnology and Biological Sciences Research Council for funding the South West Biosciences Doctoral Training Partnership (BB/ J014400/1) and a responsive-mode grant (BB/R00661X/1). We thank the University of Bristol School of Chemistry Mass Spectrometry Facility for access to the EPSRC-funded Bruker Ultraflex MALDI-TOF/TOF instrument (EP/K03927X/1). We thank the MX group at Diamond Light Source for their support. D.N.W. holds a Royal Society Wolfson Research Merit Award (WM140008).
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Thomson, Dr Drew
Authors: Rhys, G. G., Wood, C. W., Beesley, J. L., Zaccai, N. R., Burton, A. J., Brady, R. L., Thomson, A. R., and Woolfson, D. N.
College/School:College of Science and Engineering > School of Chemistry
Journal Name:Journal of the American Chemical Society
Publisher:American Chemical Society
ISSN:0002-7863
ISSN (Online):1520-5126
Published Online:08 May 2019
Copyright Holders:Copyright © 2019 American Chemical Society
First Published:First published in Journal of the American Chemical Society 141(22): 8787-8797
Publisher Policy:Reproduced in accordance with the publisher copyright policy

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