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The Tat system proofreads FeS protein substrates and directly initiates the disposal of rejected molecules

Matos, Cristina F.R.O., Robinson, Colin, Di Cola, Alessandra (2008) The Tat system proofreads FeS protein substrates and directly initiates the disposal of rejected molecules. Embo Journal, 27 (15). pp. 2055-2063. ISSN 0261-4189. (doi:10.1038/emboj.2008.132) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)

The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided. (Contact us about this Publication)
Official URL
http://dx.doi.org/10.1038/emboj.2008.132

Abstract

The twin?arginine translocation (Tat) system transports folded proteins across the bacterial plasma membrane, including FeS proteins that receive their cofactors in the cytoplasm. We have studied two Escherichia coli Tat substrates, NrfC and NapG, to examine how, or whether, the system exports only correctly folded and assembled FeS proteins. With NrfC, substitutions in even one of four predicted FeS centres completely block export, indicating an effective proofreading activity. The FeS mutants are rapidly degraded but only if they interact with the Tat translocon; they are stable in a tat deletion strain and equally stable in wild?type cells if the signal peptide twin?arginine motif is removed to block targeting. Basically similar results are obtained with NapG. The Tat apparatus thus proofreads these substrates and directly initiates the turnover of rejected molecules. Turnover of mutated FeS substrates is completely dependent on the TatA/E subunits that are believed to be involved in the late stages of translocation, and we propose that partial translocation triggers substrate turnover within an integrated quality control system for FeS proteins.

Item Type: Article
DOI/Identification number: 10.1038/emboj.2008.132
Uncontrolled keywords: FeS protein, protein transport, signal peptide Tat, twin-arginine
Subjects: Q Science > QH Natural history > QH301 Biology
Divisions: Faculties > Sciences > School of Biosciences
Depositing User: Colin Robinson
Date Deposited: 24 Jul 2013 15:50 UTC
Last Modified: 29 May 2019 10:26 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/34856 (The current URI for this page, for reference purposes)
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