9HGA

BAM-SurA-darobactin complex in the swing-out state

This is a non-PDB format compatible entry.

Summary for 9HGA

• Entry DOI: 10.2210/pdb9hga/pdb
• EMDB information: 52132
• Related PRD ID: PRD_002330
• Descriptor: Outer membrane protein assembly factor BamA, Outer membrane protein assembly factor BamB, Outer membrane protein assembly factor BamC, ... (7 entities in total)
• Functional Keywords: insertase, outer membrane protein, chaperone, protein folding, protein complex, darobactin, membrane protein
• Biological source: Escherichia coli K-12; More
• Total number of polymer chains: 7
• Total formula weight: 247636.54

Authors

Lehner, P.A.,Jakob, R.P.,Hiller, S. (deposition date: 2024-11-19, release date: 2025-04-16)

Primary citation

Lehner, P.A.,Degen, M.,Jakob, R.P.,Modaresi, S.M.,Callon, M.,Burmann, B.M.,Maier, T.,Hiller, S.
Architecture and conformational dynamics of the BAM-SurA holo insertase complex.
Sci Adv, 11:eads6094-eads6094, 2025

PubMed Abstract: The proper folding of outer membrane proteins in Gram-negative bacteria relies on their delivery to the β-barrel assembly machinery (BAM) complex. The mechanism by which survival protein A (SurA), the major periplasmic chaperone, facilitates this process is not well understood. We determine the structure of the holo insertase complex, where SurA binds BAM for substrate delivery. High-resolution cryo-electron microscopy structures of four different states and a three-dimensional variability analysis show that the holo insertase complex has a large motional spectrum. SurA bound to BAM can undergo a large swinging motion between two states. This motion is uncoupled from the conformational flexibility of the BamA barrel, which can open and close without affecting SurA binding. Notably, we observed conformational coupling of the SurA swing state and the carboxyl-terminal helix grip domain of BamC. Substrate delivery by SurA to BAM appears to follow a concerted motion that encodes a gated delivery pathway through the BAM accessory proteins to the membrane entry site.

PubMed: 40184469
DOI: 10.1126/sciadv.ads6094

Experimental method

ELECTRON MICROSCOPY (3.62 Å)