An octameric PqiC toroid stabilises the outer-membrane interaction of the PqiABC transport system

DOI: 10.1038/s44319-023-00014-4

Authors: Benjamin F. Cooper (University of Oxford) , Giedrė Ratkevičiūtė (University of Oxford) , Luke A. Clifton (ISIS Pulsed Neutron & Muon Source) , Hannah Johnston (University of Birmingham) , Rachel Holyfield (University of Birmingham) , David J. Hardy (University of Birmingham) , Simon G. Caulton (University of Birmingham) , William Chatterton (University of Birmingham) , Pooja Sridhar (University of Birmingham) , Peter Wotherspoon (University of Birmingham) , Gareth W. Hughes (University of Birmingham) , Stephen C. L. Hall (ISIS Pulsed Neutron & Muon Source) , Andrew L. Lovering (University of Birmingham) , Timothy J. Knowles (University of Birmingham)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Embo Reports , VOL 68

State: Published (Approved)
Published: January 2024
Diamond Proposal Number(s): 26803

Abstract: The E. coli Paraquat Inducible (Pqi) Pathway is a putative Gram-negative phospholipid transport system. The pathway comprises three components: an integral inner membrane protein (PqiA), a periplasmic spanning MCE family protein (PqiB) and an outer membrane lipoprotein (PqiC). Interactions between all complex components, including stoichiometry, remain uncharacterised; nevertheless, once assembled into their quaternary complex, the trio of Pqi proteins are anticipated to provide a continuous channel between the inner and outer membranes of diderms. Here, we present X-ray structures of both the native and a truncated, soluble construct of the PqiC lipoprotein, providing insight into its biological assembly, and utilise neutron reflectometry to characterise the nature of the PqiB-PqiC-membrane interaction. Finally, we employ phenotypic complementation assays to probe specific PqiC residues, which imply the interaction between PqiB and PqiC is less intimate than previously anticipated.

Diamond Keywords: Bacteria

Subject Areas: Biology and Bio-materials, Chemistry


Instruments: I04-Macromolecular Crystallography

Other Facilities: OFFSPEC at ISIS

Added On: 22/01/2024 09:01

Discipline Tags:

Biochemistry Chemistry Structural biology Life Sciences & Biotech

Technical Tags:

Diffraction Macromolecular Crystallography (MX)