Download MendeleyAn octameric PqiC toroid stabilises the outer-membrane interaction of the PqiABC transport system.
Cooper, B.F., Ratkeviciute, G., Clifton, L.A., Johnston, H., Holyfield, R., Hardy, D.J., Caulton, S.G., Chatterton, W., Sridhar, P., Wotherspoon, P., Hughes, G.W., Hall, S.C., Lovering, A.L., Knowles, T.J.(2024) EMBO Rep 25: 82-101
- PubMed: 38228789
- DOI: https://doi.org/10.1038/s44319-023-00014-4
- Primary Citation of Related Structures:
8Q2C, 8Q2D - PubMed 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.
Organizational Affiliation:
Sir William Dunn School of Pathology, University of Oxford, OX1 3RE, Oxford, UK.
