The twin-arginine translocation pathway is a major route of protein export in <i>Streptomyces coelicolor</i>
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- David A. Widdick
- Departments of *Molecular Microbiology and
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- Kieran Dilks
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104
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- Govind Chandra
- Departments of *Molecular Microbiology and
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- Andrew Bottrill
- Biological Chemistry, John Innes Centre, Norwich NR4 7UH, United Kingdom;
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- Mike Naldrett
- Biological Chemistry, John Innes Centre, Norwich NR4 7UH, United Kingdom;
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- Mechthild Pohlschröder
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104
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- Tracy Palmer
- Departments of *Molecular Microbiology and
抄録
<jats:p> The twin-arginine translocation (Tat) pathway is a protein transport system for the export of folded proteins. Substrate proteins are targeted to the Tat translocase by N-terminal signal peptides harboring a distinctive R-R-x-Φ-Φ “twin-arginine” amino acid motif. Using a combination of proteomic techniques, the protein contents from the cell wall of the model Gram-positive bacterium <jats:italic>Streptomyces coelicolor</jats:italic> were identified and compared with that of mutant strains defective in Tat transport. The proteomic experiments pointed to 43 potentially Tat-dependent extracellular proteins. Of these, 25 were verified as bearing bona fide Tat-targeting signal peptides after independent screening with a facile, rapid, and sensitive reporter assay. The identified Tat substrates, among others, include polymer-degrading enzymes, phosphatases, and binding proteins as well as enzymes involved in secondary metabolism. Moreover, in addition to predicted extracellular substrates, putative lipoproteins were shown to be Tat-dependent. This work provides strong experimental evidence that the Tat system is used as a major general export pathway in <jats:italic>Streptomyces</jats:italic> . </jats:p>
収録刊行物
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- Proceedings of the National Academy of Sciences
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Proceedings of the National Academy of Sciences 103 (47), 17927-17932, 2006-11-21
Proceedings of the National Academy of Sciences