Signal peptide–chaperone interactions on the twin-arginine protein transport pathway

TY - JOUR

T1 - Signal peptide–chaperone interactions on the twin-arginine protein transport pathway

AU - Hatzixanthis, Kostas

AU - Clarke, Thomas A.

AU - Oubrie, Arthur

AU - Richardson, David J.

AU - Turner, Raymond J.

AU - Sargent, Frank

A2 - Randall, Linda L.

N1 - dc.publisher: National Academy of Sciences

PY - 2005

Y1 - 2005

N2 - The twin-arginine transport (Tat) system is a protein-targeting pathway of prokaryotes and chloroplasts. Most Escherichia coli Tat substrates are complex metalloenzymes that must be correctly folded and assembled before transport, and a preexport chaperone-mediated “proofreading” process is therefore in operation. The paradigm proofreading chaperone is TorD, which coordinates maturation and export of the key respiratory enzyme trimethylamine N-oxide reductase (TorA). It is demonstrated here that purified TorD binds tightly and with exquisite specificity to the TorA twin-arginine signal peptide in vitro. It is also reported that the TorD family constitutes a hitherto unexpected class of nucleotide-binding proteins. The affinity of TorD for GTP is enhanced by initial signal peptide binding, and it is proposed that GTP governs signal peptide binding-and-release cycles during Tat proofreading.

AB - The twin-arginine transport (Tat) system is a protein-targeting pathway of prokaryotes and chloroplasts. Most Escherichia coli Tat substrates are complex metalloenzymes that must be correctly folded and assembled before transport, and a preexport chaperone-mediated “proofreading” process is therefore in operation. The paradigm proofreading chaperone is TorD, which coordinates maturation and export of the key respiratory enzyme trimethylamine N-oxide reductase (TorA). It is demonstrated here that purified TorD binds tightly and with exquisite specificity to the TorA twin-arginine signal peptide in vitro. It is also reported that the TorD family constitutes a hitherto unexpected class of nucleotide-binding proteins. The affinity of TorD for GTP is enhanced by initial signal peptide binding, and it is proposed that GTP governs signal peptide binding-and-release cycles during Tat proofreading.

KW - Protein transport

KW - Twin arginine signal peptide

KW - Tat pathway

U2 - 10.1073/pnas.0500737102

DO - 10.1073/pnas.0500737102

M3 - Article

SN - 0027-8424

VL - 102

SP - 8460

EP - 8465

JO - Proceedings of the National Academy of Sciences of the United States of America

JF - Proceedings of the National Academy of Sciences of the United States of America

IS - 24

ER -