Genetic evidence for a TatC dimer at the core of the Escherichia coli twin arginine (Tat) protein translocase.

The twin arginine protein transport (Tat) system transports folded proteins across the cytoplasmic membranes of prokaryotes and the thylakoid membranes of plant chloroplasts. In Escherichia coli, the TatB and TatC components form a multivalent receptor complex that binds Tat substrates. Here, we hav...

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Main Authors: Maldonado, B, Buchanan, G, Müller, M, Berks, B, Palmer, T
Format: Journal article
Language:English
Published: 2011
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author Maldonado, B
Buchanan, G
Müller, M
Berks, B
Palmer, T
author_facet Maldonado, B
Buchanan, G
Müller, M
Berks, B
Palmer, T
author_sort Maldonado, B
collection OXFORD
description The twin arginine protein transport (Tat) system transports folded proteins across the cytoplasmic membranes of prokaryotes and the thylakoid membranes of plant chloroplasts. In Escherichia coli, the TatB and TatC components form a multivalent receptor complex that binds Tat substrates. Here, we have used a genetic fusion approach to construct covalent TatC oligomers in order to probe the organisation of TatC. A fused dimer of TatC supported Tat transport activity and was fully stable in vivo. Inactivating point mutations in one or other of the TatC units in the fused TatC dimer did not inactivate TatC function, indicating that only one TatC protomer in the TatC fused dimer needs to be active. Larger covalent fusions of TatC also supported Tat transport activity but were degraded in vivo to release smaller TatC forms. Taken together, these results strongly suggest that TatC forms a functional dimer, and support the idea that there is an even number of TatC protomers in the TatBC complex.
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spelling oxford-uuid:25dddc52-78fc-4d80-aae2-77353980f1cc2022-03-26T11:57:52ZGenetic evidence for a TatC dimer at the core of the Escherichia coli twin arginine (Tat) protein translocase.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:25dddc52-78fc-4d80-aae2-77353980f1ccEnglishSymplectic Elements at Oxford2011Maldonado, BBuchanan, GMüller, MBerks, BPalmer, TThe twin arginine protein transport (Tat) system transports folded proteins across the cytoplasmic membranes of prokaryotes and the thylakoid membranes of plant chloroplasts. In Escherichia coli, the TatB and TatC components form a multivalent receptor complex that binds Tat substrates. Here, we have used a genetic fusion approach to construct covalent TatC oligomers in order to probe the organisation of TatC. A fused dimer of TatC supported Tat transport activity and was fully stable in vivo. Inactivating point mutations in one or other of the TatC units in the fused TatC dimer did not inactivate TatC function, indicating that only one TatC protomer in the TatC fused dimer needs to be active. Larger covalent fusions of TatC also supported Tat transport activity but were degraded in vivo to release smaller TatC forms. Taken together, these results strongly suggest that TatC forms a functional dimer, and support the idea that there is an even number of TatC protomers in the TatBC complex.
spellingShingle Maldonado, B
Buchanan, G
Müller, M
Berks, B
Palmer, T
Genetic evidence for a TatC dimer at the core of the Escherichia coli twin arginine (Tat) protein translocase.
title Genetic evidence for a TatC dimer at the core of the Escherichia coli twin arginine (Tat) protein translocase.
title_full Genetic evidence for a TatC dimer at the core of the Escherichia coli twin arginine (Tat) protein translocase.
title_fullStr Genetic evidence for a TatC dimer at the core of the Escherichia coli twin arginine (Tat) protein translocase.
title_full_unstemmed Genetic evidence for a TatC dimer at the core of the Escherichia coli twin arginine (Tat) protein translocase.
title_short Genetic evidence for a TatC dimer at the core of the Escherichia coli twin arginine (Tat) protein translocase.
title_sort genetic evidence for a tatc dimer at the core of the escherichia coli twin arginine tat protein translocase
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AT mullerm geneticevidenceforatatcdimeratthecoreoftheescherichiacolitwinargininetatproteintranslocase
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