Initial assembly steps of a translocase for folded proteins
| Autor: | Julia Fröbel, Laura A. Haag, Matthias Müller, Ekaterina Eimer, Anne-Sophie Blümmel |
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| Rok vydání: | 2015 |
| Předmět: |
Models
Molecular Twin-Arginine-Translocation System Protein Folding Multidisciplinary Molecular Sequence Data General Physics and Astronomy General Chemistry Plasma protein binding Biology Article General Biochemistry Genetics and Molecular Biology Twin-arginine translocation pathway chemistry.chemical_compound Membrane Membrane protein chemistry Biochemistry TATB Biophysics biology.protein Translocase Protein folding Amino Acid Sequence Peptide sequence Protein Binding |
| Zdroj: | Nature Communications |
| ISSN: | 2041-1723 |
| DOI: | 10.1038/ncomms8234 |
| Popis: | The so-called Tat (twin-arginine translocation) system transports completely folded proteins across cellular membranes of archaea, prokaryotes and plant chloroplasts. Tat-directed proteins are distinguished by a conserved twin-arginine (RR-) motif in their signal sequences. Many Tat systems are based on the membrane proteins TatA, TatB and TatC, of which TatB and TatC are known to cooperate in binding RR-signal peptides and to form higher-order oligomeric structures. We have now elucidated the fine architecture of TatBC oligomers assembled to form closed intramembrane substrate-binding cavities. The identification of distinct homonymous and heteronymous contacts between TatB and TatC suggest that TatB monomers coalesce into dome-like TatB structures that are surrounded by outer rings of TatC monomers. We also show that these TatBC complexes are approached by TatA protomers through their N-termini, which thereby establish contacts with TatB and membrane-inserted RR-precursors. The twin-arginine translocation complex consists of TatA, TatB and TatC subunits and transports folded proteins across cellular membranes. Here, using photocrosslinking, the authors show that TatB monomers form dome-like structures that are surrounded by TatC monomers enabling lateral access of TatA. |
| Databáze: | OpenAIRE |
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