Sutherland, G.A. orcid.org/0000-0002-6319-4637, Grayson, K.J., Adams, N.B.P. orcid.org/0000-0003-3080-3448 et al. (12 more authors) (2018) Probing the quality control mechanism of the Escherichia coli twin-arginine translocase with folding variants of ade novo-designed heme protein. Journal of Biological Chemistry, 293 (18). pp. 6672-6681. ISSN 0021-9258
Abstract
Protein transport across the cytoplasmic membrane of bacterial cells is mediated by either the general secretion (Sec) system or the twin arginine translocase (Tat). The Tat machinery exports folded and cofactor containing proteins from the cytoplasm to the periplasm by using the transmembrane proton motive force as a source of energy. The Tat apparatus apparently senses the folded state of its protein substrates, a quality control mechanism that prevents premature export of nascent unfolded or misfolded polypeptides, but its mechanistic basis has not yet been determined. Here, we investigated the innate ability of the modelEscherichia coliTat system to recognize and translocatede novo-designed protein substrates with experimentally determined differences in the extent of folding. Water-soluble, four-helix bundle maquette proteins were engineered to bind two, one or no hemebcofactors, resulting in a concomitant reduction in the extent of their folding, assessed with temperature-dependent CD spectroscopy and one-dimensional1H NMR spectroscopy. Fusion of the archetypal N-terminal Tat signal peptide of theEcolitrimethylamine-N-oxide (TMAO) reductase (TorA) to the N-terminus of the protein maquettes was sufficient for the Tat system to recognize them as substrates. The clear correlation between the level of Tat-dependent export and the degree of hemeb-induced folding of the maquette protein suggested that the membrane-bound Tat machinery can sense the extent of folding and conformational flexibility of its substrates. We propose that these artificial proteins are ideal substrates for future investigations of the Tat system's quality control mechanism.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2018 American Society for Biochemistry and Molecular Biology. This is an author produced version of a paper subsequently published in Journal of Biological Chemistry. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | protein design; twin-arginine translocase; protein folding; maquette; Escherichia coli; protein translocation; biotechnology; protein quality control; Tat system; protein export |
Dates: |
|
Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > School of Biosciences (Sheffield) > Department of Molecular Biology and Biotechnology (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 05 Apr 2018 08:31 |
Last Modified: | 16 Nov 2020 12:28 |
Status: | Published |
Publisher: | American Society for Biochemistry and Molecular Biology |
Refereed: | Yes |
Identification Number: | 10.1074/jbc.RA117.000880 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:129209 |