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Updated: Jun 27, 2026

Toeprinting Analysis of Translation Initiation Complex Formation on Mammalian mRNAs
Published on: May 10, 2018
Features of a twin-arginine signal peptide required for recognition by a Tat proofreading chaperone
Grant Buchanan1, Julien Maillard, Sander B Nabuurs
1Division of Molecular and Environmental Microbiology, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, Scotland, United Kingdom.
Abstract:
The twin-arginine translocation (Tat) system is a bacterial protein targeting pathway. Tat-targeted proteins display signal peptides containing a distinctive SRRxFLK 'twin-arginine' motif. The Escherichia coli trimethylamine N-oxide reductase (TorA) bears a bifunctional Tat signal peptide, which directs protein export and serves as a binding site for the TorD biosynthetic chaperone. Here, the physical interaction between TorD and the TorA signal peptide was investigated. A single substitution within the TorA signal peptide (L31Q) was sufficient to impair TorD binding. Screening of a random torD mutant library identified a variant TorD protein (Q7L) that displayed increased binding affinity for the TorA signal peptide.
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