Malfolded recombinant Tat substrates are Tat-independently degraded in Escherichia coli

authored by

Ute Lindenstrauß, Cristina F.R.O. Matos, Wenke Graubner, Colin Robinson, Thomas Brüser

Abstract

The twin-arginine translocation (Tat) system translocates folded proteins across biological membranes. It has been suggested that the Tat system of Escherichia coli can direct Tat substrates to degradation if they are not properly folded [Matos, C.F., Robinson, C. and Di Cola, A. (2008) The Tat system proofreads FeS protein substrates and directly initiates the disposal of rejected molecules. EMBO J. 27, 2055-2063; Matos, C.F., Di Cola, A. and Robinson, C. (2009) TatD is a central component of a Tat translocon-initiated quality control system for exported FeS proteins in Escherichia coli. EMBO Rep. 10, 474-479]. Contrary to the earlier reports, it is now concluded that reported differences between tested strains were due to variations in expression levels and inclusion body formation. Using the native Tat substrate NrfC and a malfolded variant thereof, we show that the turnover of these proteins is not affected by the absence of all known Tat components. Malfolded NrfC is degraded more quickly than the native protein, indicating that Tat-independent protease systems can recognize malfolded Tat substrates.

Organisation(s)

Institute of Microbiology

External Organisation(s)

Martin Luther University Halle-Wittenberg
University of Warwick

Type

Article

Journal

FEBS letters

Volume

584

Pages

3644-3648

No. of pages

5

ISSN

0014-5793

Publication date

08.2010

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Biophysics, Structural Biology, Biochemistry, Molecular Biology, Genetics, Cell Biology

Electronic version(s)

https://doi.org/10.1016/j.febslet.2010.07.039 (Access: Open)