{
  "abstract": "The mechanism by which glycerophospholipids are transported between the inner and outer membranes in Gram-negative bacteria remains poorly understood. In Escherichia coli, the paraquat-inducible (Pqi) pathway, comprising the inner membrane protein PqiA, the periplasm-spanning MCE-family protein PqiB, and the outer membrane lipoprotein PqiC, has been implicated in this process. These components are proposed to assemble into a quaternary complex that forms a continuous channel bridging the inner and outer membranes. Here, using neutron reflectometry and quartz crystal microbalance with dissipation monitoring, we perform a dynamic structural analysis of PqiABC within a planar double bilayer membrane-mimetic system. This approach reveals that PqiABC assembles into a stable, envelope-spanning complex anchored to both membranes, consistent with its proposed conduit architecture. Furthermore, using neutron reflectometry in combination with complementary fluorescence-based assays, we demonstrate that PqiABC mediates passive glycerophospholipid transport, supporting bidirectional lipid exchange between membranes. Together, these findings establish PqiABC as a membrane-bridging lipid transport system and provide direct evidence for a mechanism of passive glycerophospholipid equilibration across the bacterial envelope.",
  "abstract_shown": true,
  "affiliations": [
    "School of Biosciences, University of Birmingham, UK. B15 2TT"
  ],
  "article_type": "New results",
  "arxiv": null,
  "author_total": 10,
  "authors": [
    {
      "name": "H. E. Johnston"
    },
    {
      "name": "L. A. Clifton"
    },
    {
      "name": "C. B. Wilson"
    },
    {
      "name": "P. Sridhar"
    },
    {
      "name": "A. Alzahrani"
    },
    {
      "name": "A. Colyer"
    },
    {
      "name": "R. Logan"
    },
    {
      "name": "S. C. L. Hall"
    },
    {
      "name": "D. J. Hardy"
    },
    {
      "affs": [
        0
      ],
      "name": "T. J. Knowles"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/0fz61f16fnhkb.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.09.15.751761",
  "fulltext_url": "https://www.biorxiv.org/content/10.64898/2026.09.15.751761v1.full",
  "id": "0fz61f16fnhkb",
  "issns": [],
  "landing_url": "https://www.biorxiv.org/content/10.64898/2026.09.15.751761v1",
  "language": null,
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "biorxiv",
      "biophysics"
    ],
    [
      "openalex",
      "1311|Bacterial Genetics and Biotechnology"
    ]
  ],
  "openalex": "W7213471086",
  "pdf_url": "https://www.biorxiv.org/content/10.64898/2026.09.15.751761v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-15",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/0fz61f16fnhkb.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:22:50Z",
      "native_id": "10.64898/2026.09.15.751761",
      "source": "biorxiv",
      "url": "https://www.biorxiv.org/content/10.64898/2026.09.15.751761v1"
    }
  ],
  "subjects": [
    {
      "field": "biochemistry",
      "origin": "biorxiv:biophysics",
      "subfield": "biophysics"
    }
  ],
  "title": "PqiABC forms a membrane-bridging conduit and mediates bidirectional phospholipid transport across the Gram-negative bacterial envelope",
  "title_text": "PqiABC forms a membrane-bridging conduit and mediates bidirectional phospholipid transport across the Gram-negative bacterial envelope",
  "type": "preprint",
  "updated_at": "2026-10-30T12:22:50Z",
  "url": "https://research.draconitic.com/paper/0fz61f16fnhkb",
  "venue": "bioRxiv",
  "versions": []
}