9QGY

Structure of the YbjP lipoprotein bound to the MacAB-TolC tripartite efflux pump

Summary for 9QGY

• Entry DOI: 10.2210/pdb9qgy/pdb
• EMDB information: 53150
• Descriptor: Outer membrane protein TolC, Uncharacterized lipoprotein YbjP, Macrolide export protein MacA, ... (7 entities in total)
• Functional Keywords: multi-drug efflux pump, macab-tolc, acrabz-tolc, type i secretion, lipoprotein, membrane protein assembly, membrane protein
• Biological source: Escherichia coli; More
• Total number of polymer chains: 14
• Total formula weight: 498059.23

Authors

Kaplan, E.,Horne, J.,Luisi, B.F. (deposition date: 2025-03-14, release date: 2026-03-25, Last modification date: 2026-10-07)

Primary citation

Horne, J.,Kaplan, E.,Jin, B.,Abbott, K.,Flores, V.,Petsolari, E.,Gradon, J.,Ntsogo, Y.,Harris, A.,Yu, D.,Zarkan, A.,Luisi, B.F.
A lipoprotein partner for the Escherichia coli outer membrane protein TolC.
Elife, 15:-, 2026

PubMed Abstract: The outer membrane protein TolC from belongs to an extensive superfamily whose members are found throughout the didermal, Gram-negative bacterial lineages. The protein serves as an activated exit duct in multi-drug efflux pumps and protein secretion machinery. Many TolC homologues bear a lipid modification on the N-terminus that embeds into the inner leaflet of the outer membrane and appears to have been a conserved feature; however, the moiety is absent entirely in the TolC. We have discovered that the lipoprotein YbjP interacts extensively with the periplasmic surface of TolC and its N-terminal lipid moiety is embedded in the membrane, mimicking the intramolecular and modification-membrane interactions seen in TolC homologues. Here, we present cryo-EM structures of the MacA-MacB-TolC and AcrA-AcrB-TolC tripartite pumps complexed to YbjP. Although the association occurs spontaneously both in vitro and in vivo, the YbjP-TolC interaction is not required for efflux activity under standard laboratory conditions. YbjP may contribute to stabilising the orientation and distribution of TolC in the outer membrane, as well as the expression of transporters for tryptophan and cyclic peptide toxins.

PubMed: 41984076
DOI: 10.7554/eLife.110666

Experimental method

ELECTRON MICROSCOPY (2.48 Å)