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The Escherichia coli TatABC system and a Bacillus subtilis TatAC-type system recognise three distinct targeting determinants in twin-arginine signal peptides.

Mendel, Sharon, McCarthy, Andrew, Barnett, James P., Eijlander, Robyn T., Nenninger, Anja, Kuipers, Oscar P., Robinson, Colin (2008) The Escherichia coli TatABC system and a Bacillus subtilis TatAC-type system recognise three distinct targeting determinants in twin-arginine signal peptides. Journal of Molecular Biology, 375 (3). pp. 661-72. ISSN 0022-2836. (doi:10.1016/j.jmb.2007.09.087) (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/10.1016/j.jmb.2007.09.087

Abstract

The Tat system transports folded proteins across bacterial and thylakoid membranes. In Gram-negative organisms, it is encoded by tatABC genes and the system recognizes substrates bearing signal peptides with a conserved twin-arginine motif. Most Gram-positive organisms lack a tatB gene, indicating major differences in organisation and/or mechanism. Here, we have characterized the essential targeting determinants that are recognized by a Bacillus subtilis TatAC-type system, TatAdCd. Substitution by lysine of either of the twin-arginine residues in the TorA signal peptide can be tolerated, but the presence of twin-lysine residues blocks export completely. We show that additional determinants can be as important as the twin-arginine motif. Replacement of the -1 serine by alanine, in either the TorA or DmsA signal peptide, almost blocks export by either the B. subtilis TatAdCd or Escherichia coli TatABC systems, firmly establishing the importance of this -1 residue in these signal peptides. Surprisingly, the +2 leucine in the DmsA signal peptide (sequence SRRGLV) appears to play an equally important role and substitution by alanine or phenylalanine blocks export by both the B. subtilis and E. coli systems. These data identify three distinct determinants, whose importance varies depending on the signal peptide in question. The data also show that the B. subtilis TatAdCd and E. coli TatABC systems recognize very similar determinants within their target peptides, and exhibit surprisingly similar responses to mutations within these determinants.

Item Type: Article
DOI/Identification number: 10.1016/j.jmb.2007.09.087
Subjects: Q Science > QH Natural history > QH301 Biology
Divisions: Faculties > Sciences > School of Biosciences
Depositing User: Colin Robinson
Date Deposited: 24 Jul 2013 15:52 UTC
Last Modified: 29 May 2019 10:26 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/34857 (The current URI for this page, for reference purposes)
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