5ABB

Visualization of a polytopic membrane protein during SecY-mediated membrane insertion

Summary for 5ABB

• Entry DOI: 10.2210/pdb5abb/pdb
• EMDB information: 2446
• Descriptor: PROTEIN TRANSLOCASE SUBUNIT SECY, PROTEIN TRANSLOCASE SUBUNIT SECE, GREEN-LIGHT ABSORBING PROTEORHODOPSIN (3 entities in total)
• Functional Keywords: translation, ribosome, membrane protein, translocon
• Biological source: ESCHERICHIA COLI; More
• Cellular location: Cell inner membrane ; Multi-pass membrane protein . Membrane ; Multi-pass membrane protein : B7MCR5; Cell membrane ; Multi-pass membrane protein : Q9F7P4
• Total number of polymer chains: 3
• Total formula weight: 68811.35

Authors

Bischoff, L.,Wickles, S.,Berninghausen, O.,vanderSluis, E.,Beckmann, R. (deposition date: 2015-08-05, release date: 2015-08-19, Last modification date: 2024-05-08)

Primary citation

Bischoff, L.,Wickles, S.,Berninghausen, O.,Van Der Sluis, E.O.,Beckmann, R.
Visualization of a Polytopic Membrane Protein During Secy-Mediated Membrane Insertion.
Nat.Commun., 5:4103-, 2014

PubMed Abstract: The biogenesis of polytopic membrane proteins occurs co-translationally on ribosomes that are tightly bound to a membrane-embedded protein-conducting channel: the Sec-complex. The path that is followed by nascent proteins inside the ribosome and the Sec-complex is relatively well established; however, it is not clear what the fate of the N-terminal transmembrane domains (TMDs) of polytopic membrane proteins is when the C-terminal TMDs domains are not yet synthesized. Here, we present the sub-nanometer cryo-electron microscopy structure of an in vivo generated ribosome-SecY complex that carries a membrane insertion intermediate of proteorhodopsin (PR). The structure reveals a pre-opened Sec-complex and the first two TMDs of PR already outside the SecY complex directly in front of its proposed lateral gate. Thus, our structure is in agreement with positioning of N-terminal TMDs at the periphery of SecY, and in addition, it provides clues for the molecular mechanism underlying membrane protein topogenesis.

PubMed: 24912953
DOI: 10.1038/NCOMMS5103

Experimental method

ELECTRON MICROSCOPY (8 Å)