8VLW

TolQ-TolR inner membrane protein complex from Acinetobacter baumannii

Summary for 8VLW

• Entry DOI: 10.2210/pdb8vlw/pdb
• EMDB information: 43346
• Descriptor: Tol-Pal system protein TolQ, Tol-Pal system protein TolR (2 entities in total)
• Functional Keywords: inner membrane protein complex, structural genomics, center for structural biology of infectious diseases, csbid, membrane protein
• Biological source: Acinetobacter baumannii; More
• Total number of polymer chains: 7
• Total formula weight: 129507.42

Authors

Guo, Y.,Borek, D.,Center for Structural Biology of Infectious Diseases (CSBID) (deposition date: 2024-01-12, release date: 2025-01-15, Last modification date: 2025-01-22)

Primary citation

Karimullina, E.,Guo, Y.,Khan, H.M.,Emde, T.,Quade, B.,Leo, R.D.,Otwinowski, Z.,Tieleman Peter, D.,Borek, D.,Savchenko, A.
Structural architecture of TolQ-TolR inner membrane protein complex from opportunistic pathogen Acinetobacter baumannii.
Biorxiv, 2024

PubMed Abstract: Gram-negative bacteria harness the proton motive force (PMF) within their inner membrane (IM) to uphold the integrity of their cell envelope, an indispensable aspect for both division and survival. The IM TolQ-TolR complex is the essential part of the Tol-Pal system, serving as a conduit for PMF energy transfer to the outer membrane. Here we present cryo-EM reconstructions of TolQ in apo and TolR- bound forms at atomic resolution. The apo TolQ configuration manifests as a symmetric pentameric pore, featuring a trans-membrane funnel leading towards a cytoplasmic chamber. In contrast, the TolQ-TolR complex assumes a proton non-permeable stance, characterized by the TolQ pentamer's flexure to accommodate the TolR dimer, where two protomers undergo a translation-based relationship. Our structure-guided analysis and simulations support the rotor-stator mechanism of action, wherein the rotation of the TolQ pentamer harmonizes with the TolR protomers' interplay. These findings broaden our mechanistic comprehension of molecular stator units empowering critical functions within the Gram-negative bacterial cell envelope.

PubMed: 38948712
DOI: 10.1101/2024.06.19.599759

Experimental method

ELECTRON MICROSCOPY (3.34 Å)