Initial assembly steps of a translocase for folded proteins.
Nat Commun
; 6: 7234, 2015 Jun 11.
Article
en En
| MEDLINE
| ID: mdl-26068441
ABSTRACT
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.
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1
Banco de datos:
MEDLINE
Asunto principal:
Sistema de Translocación de Arginina Gemela
Idioma:
En
Año:
2015
Tipo del documento:
Article