The University of Southampton
University of Southampton Institutional Repository

A new type of signal peptide: Central role of a twin-arginine motif in transfer signals for the ΔpH-dependent thylakoidal protein translocase

A new type of signal peptide: Central role of a twin-arginine motif in transfer signals for the ΔpH-dependent thylakoidal protein translocase
A new type of signal peptide: Central role of a twin-arginine motif in transfer signals for the ΔpH-dependent thylakoidal protein translocase

The ΔpH-driven and Sec-related thylakoidal protein translocases recognise distinct types of thylakoid transfer signal, yet all transfer signals resemble bacterial signal peptides in structural terms. Comparison of known transfer signals reveals a single concrete difference: signals for the ΔpH-dependent system contain a common twin-arginine motif immediately before the hydrophobic region. We show that this motif is critical for the ΔpH-driven translocation process; substitution of the arg-arg by gin-gin or even arg-lys totally blocks translocation across the thylakoid membrane, and replacement by lys-arg reduces the rate of translocation by > 100-fold. The targeting information in this type of signal thus differs fundamentally from that of bacterial signal peptides, where the required positive charge can be supplied by any basic amino acid. Insertion of a twin-arg moth into a Sec-dependent substrate does not alter the pathway followed but reduces translocation efficiency, suggesting that the motif may also repel the Sec-type system. Other information must help to specify the choice of translocation mechanism, but this information is unlikely to reside in the hydrophobic region because substitution by a hydrophobic section from an integral membrane protein does not affect the translocation pathway.

Chloroplasts, Protein transport, Signal peptide, Thylakoid biogenesis
0261-4189
2715-2722
Chaddock, A. M.
57414576-4a0f-4fc6-8ffd-d9f807897896
Mant, A.
63319e45-deeb-45ad-a30d-e05b42052a0d
Karnauchov, I.
75ebb3ce-05eb-44c3-80c0-27800bc87666
Brink, S.
7cd75349-07f5-4e4b-a4f6-e87ce7ecde1e
Herrmann, R. G.
7b49b698-cf23-47ae-b9c5-3a1b4f7603b3
Klösgen, R.B.
1ddc41f6-e95a-4c64-be98-431fb814b58c
Robinson, C.
678e0157-d628-44e8-83de-3591b07c673f
Chaddock, A. M.
57414576-4a0f-4fc6-8ffd-d9f807897896
Mant, A.
63319e45-deeb-45ad-a30d-e05b42052a0d
Karnauchov, I.
75ebb3ce-05eb-44c3-80c0-27800bc87666
Brink, S.
7cd75349-07f5-4e4b-a4f6-e87ce7ecde1e
Herrmann, R. G.
7b49b698-cf23-47ae-b9c5-3a1b4f7603b3
Klösgen, R.B.
1ddc41f6-e95a-4c64-be98-431fb814b58c
Robinson, C.
678e0157-d628-44e8-83de-3591b07c673f

Chaddock, A. M., Mant, A., Karnauchov, I., Brink, S., Herrmann, R. G., Klösgen, R.B. and Robinson, C. (1995) A new type of signal peptide: Central role of a twin-arginine motif in transfer signals for the ΔpH-dependent thylakoidal protein translocase. The EMBO Journal, 14 (12), 2715-2722.

Record type: Article

Abstract

The ΔpH-driven and Sec-related thylakoidal protein translocases recognise distinct types of thylakoid transfer signal, yet all transfer signals resemble bacterial signal peptides in structural terms. Comparison of known transfer signals reveals a single concrete difference: signals for the ΔpH-dependent system contain a common twin-arginine motif immediately before the hydrophobic region. We show that this motif is critical for the ΔpH-driven translocation process; substitution of the arg-arg by gin-gin or even arg-lys totally blocks translocation across the thylakoid membrane, and replacement by lys-arg reduces the rate of translocation by > 100-fold. The targeting information in this type of signal thus differs fundamentally from that of bacterial signal peptides, where the required positive charge can be supplied by any basic amino acid. Insertion of a twin-arg moth into a Sec-dependent substrate does not alter the pathway followed but reduces translocation efficiency, suggesting that the motif may also repel the Sec-type system. Other information must help to specify the choice of translocation mechanism, but this information is unlikely to reside in the hydrophobic region because substitution by a hydrophobic section from an integral membrane protein does not affect the translocation pathway.

Full text not available from this repository.

More information

Published date: 1995
Keywords: Chloroplasts, Protein transport, Signal peptide, Thylakoid biogenesis

Identifiers

Local EPrints ID: 413061
URI: https://eprints.soton.ac.uk/id/eprint/413061
ISSN: 0261-4189
PURE UUID: 1a7316b8-efd9-42b9-a23d-54da1e316de8

Catalogue record

Date deposited: 14 Aug 2017 16:31
Last modified: 13 Mar 2019 20:14

Export record

Contributors

Author: A. M. Chaddock
Author: A. Mant
Author: I. Karnauchov
Author: S. Brink
Author: R. G. Herrmann
Author: R.B. Klösgen
Author: C. Robinson

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of https://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×