Features of a twin-arginine signal peptide required for recognition by a Tat proofreading chaperone.
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.
Buchanan
Grant
G
Division of Molecular and Environmental Microbiology, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, Scotland, United Kingdom.
Maillard
Julien
J
Nabuurs
Sander B
SB
Richardson
David J
DJ
Palmer
Tracy
T
Sargent
Frank
F
D020816:Amino Acid Motifs; D019943:Amino Acid Substitution; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism*; D016296:Mutagenesis; D009154:Mutation; D010089:Oxidoreductases, N-Demethylating / Q000378:metabolism*; D011485:Protein Binding; D021382:Protein Sorting Signals / Q000235:genetics; D020798:Two-Hybrid System Techniques
D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; D018832:Molecular Chaperones; D021382:Protein Sorting Signals; C088083:TorD protein, E coli; C408585:twin-arginine translocase complex, E coli; D010089:Oxidoreductases, N-Demethylating; C023186:trimethylamine dehydrogenase