LolCDE lipoprotein ABC transporter complex

cellstructuremech:lolcde_lipoprotein_abc_transporter_complex · Other · Multiprotein complex · Proposed

An Escherichia coli inner-membrane ABC transporter complex composed of one LolC transmembrane subunit, two LolD ATP-binding subunits, and one LolE transmembrane subunit that uses LolD ATP hydrolysis to release outer membrane-specific lipoproteins from the inner membrane for periplasmic trafficking. [ComplexPortal:CPX-4262]

Synonyms: LolCDE complex

UniProt location names: UniProt Consortium, CC BY 4.0. Reference label and route sources.

Components

Component	Type	Part of / acts on	Grounding	Genes	Stoichiometry	Essential	Role
Lipoprotein-releasing system transmembrane protein LolC	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	lolC	1 copy in the E. coli K-12 Complex Portal CPX-4262 entry	ESSENTIAL	Inner-membrane transmembrane subunit that recognizes mature outer-membrane lipoproteins with LolE on the periplasmic side of the membrane. `ComplexPortal:CPX-4262` Complex Portal CPX-4262 curates one P0ADC3/LolC copy in the E. coli K-12 LolCDE lipoprotein ABC transporter complex. `UniProtKB:P0ADC3` UniProtKB P0ADC3 is the reviewed E. coli K-12 entry for Lipoprotein-releasing system transmembrane protein LolC. `PDB:7MDY` RCSB PDB:7MDY is an E. coli LolCDE nucleotide-bound electron-microscopy structure.
Lipoprotein-releasing system ATP-binding protein LolD	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	lolD	2 copies in the E. coli K-12 Complex Portal CPX-4262 entry	ESSENTIAL	Cytoplasmic ATP-binding subunit that forms a two-copy nucleotide-binding dimer and drives lipoprotein release by ATP hydrolysis. `ComplexPortal:CPX-4262` Complex Portal CPX-4262 curates two P75957/LolD copies in the E. coli K-12 LolCDE lipoprotein ABC transporter complex. `UniProtKB:P75957` UniProtKB P75957 is the reviewed E. coli K-12 entry for Lipoprotein-releasing system ATP-binding protein LolD. `PDB:7MDY` RCSB PDB:7MDY is an E. coli LolCDE nucleotide-bound electron-microscopy structure.
Lipoprotein-releasing system transmembrane protein LolE	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	lolE	1 copy in the E. coli K-12 Complex Portal CPX-4262 entry	ESSENTIAL	Inner-membrane transmembrane subunit that cooperates with LolC in periplasmic-side recognition and release of mature outer-membrane lipoproteins. `ComplexPortal:CPX-4262` Complex Portal CPX-4262 curates one P75958/LolE copy in the E. coli K-12 LolCDE lipoprotein ABC transporter complex. `UniProtKB:P75958` UniProtKB P75958 is the reviewed E. coli K-12 entry for Lipoprotein-releasing system transmembrane protein LolE. `PDB:7MDY` RCSB PDB:7MDY is an E. coli LolCDE nucleotide-bound electron-microscopy structure.

Organism-specific protein examples

Named proteins in which each component's role was established, with the organism the evidence comes from. The component above is the taxon-agnostic family; these are the specific entries behind it.

Lipoprotein-releasing system transmembrane protein LolC

Accession	Protein	Gene	Organism	Entry
`UniProtKB:P0ADC3`	Lipoprotein-releasing system transmembrane protein LolC	lolC	Escherichia coli K-12 (`NCBITaxon:83333`)	REVIEWED
Role and evidence (1 reference) `UniProtKB:P0ADC3` Reviewed Swiss-Prot entry LOLC_ECOLI is the E. coli K-12 LolC accession and cross-references ComplexPortal:CPX-4262.

Lipoprotein-releasing system ATP-binding protein LolD

Accession	Protein	Gene	Organism	Entry
`UniProtKB:P75957`	Lipoprotein-releasing system ATP-binding protein LolD	lolD	Escherichia coli K-12 (`NCBITaxon:83333`)	REVIEWED
Role and evidence (1 reference) `UniProtKB:P75957` Reviewed Swiss-Prot entry LOLD_ECOLI is the E. coli K-12 LolD accession and cross-references ComplexPortal:CPX-4262.

Lipoprotein-releasing system transmembrane protein LolE

Accession	Protein	Gene	Organism	Entry
`UniProtKB:P75958`	Lipoprotein-releasing system transmembrane protein LolE	lolE	Escherichia coli K-12 (`NCBITaxon:83333`)	REVIEWED
Role and evidence (1 reference) `UniProtKB:P75958` Reviewed Swiss-Prot entry LOLE_ECOLI is the E. coli K-12 LolE accession and cross-references ComplexPortal:CPX-4262.

Source composition assertions

LolCDE lipoprotein ABC transporter complex (ComplexPortal:CPX-4262)

Escherichia coli (strain K12) (NCBITaxon:83333) · Heterotetramer · ECO:0000353 · retrieved 2026-10-02

Participant	Source type	Source name	Stoichiometry
`UniProtKB:P0ADC3` — Lipoprotein-releasing system transmembrane protein LolC	protein	lolC	1
`UniProtKB:P75957` — Lipoprotein-releasing system ATP-binding protein LolD	protein	lolD	2
`UniProtKB:P75958` — Lipoprotein-releasing system transmembrane protein LolE	protein	lolE	1

Curator-scoped import: E. coli K-12 LolCDE source composition for this record. Source evidence: physical interaction evidence. The accession was resolved through the Complex Portal accession endpoint; no equivalence xref was inferred.

Canonical examples

NCBITaxon:83333 Escherichia coli K-12 — Source strain for Complex Portal CPX-4262, which curates the heterotetrameric LolCD2E lipoprotein ABC transporter composition. [ComplexPortal:CPX-4262]

Functions

lipoprotein releasing activity GO:0140306 — LolCDE recognizes mature outer-membrane lipoproteins in the inner membrane and releases them for periplasmic transport toward the outer membrane.
- GO:0140306 GO:0140306 is the molecular-function term for LolCDE-mediated lipoprotein releasing activity.
- ComplexPortal:CPX-4262 Complex Portal CPX-4262 describes LolC/LolE recognition and LolD ATP hydrolysis during lipoprotein release.

Physical properties

SUBUNIT_COUNT: 4 (E. coli K-12 LolCD2E heterotetramer in ComplexPortal:CPX-4262) [ComplexPortal:CPX-4262]

Mechanism graphs

LolCDE releases outer-membrane lipoproteins from the inner membrane (FUNCTION)

LolC, LolE, and two LolD copies form an ATP-powered inner-membrane complex that releases mature lipoproteins for delivery to the outer membrane.

Subject	Predicate	Object	Evidence
Lipoprotein-releasing system transmembrane protein LolC	recognizes with	Lipoprotein-releasing system transmembrane protein LolE	`ComplexPortal:CPX-4262` CPX-4262 describes lipoprotein recognition by LolC and/or LolE on the periplasmic side of the inner membrane.
Lipoprotein-releasing system ATP-binding protein LolD	powers	lipoprotein releasing activity	`ComplexPortal:CPX-4262` CPX-4262 describes LolD ATP hydrolysis as the driving force for lipoprotein release.
LolCDE lipoprotein ABC transporter complex	enables	lipoprotein releasing activity	`GO:0140306` GO:0140306 defines lipoprotein releasing activity as mediated by the LolCDE complex.
lipoprotein releasing activity	releases	mature outer-membrane lipoprotein	`GO:0140306` GO:0140306 specifies mature outer membrane lipoproteins in the inner membrane as the substrates of LolCDE-mediated release.
mature outer-membrane lipoprotein	leaves	inner membrane	`GO:0140306` GO:0140306 describes release of mature outer-membrane lipoproteins from the inner membrane.
lipoprotein localization to outer membrane	targets	outer membrane	`GO:0044874` GO:0044874 is the biological-process term for localization of lipoproteins to an outer membrane.

Discussions

CURATION_TODO (OPEN): Resolve exact source-neutral protein-family groundings for LolC, LolD, and LolE before replacing their reviewed-label-only component rows. ComplexPortal:CPX-4262, PDB:7MDY, and the reviewed E. coli K-12 UniProt records exactly identify the three LolCDE proteins, but no InterPro, Pfam, NCBIfam, or GO accession was verified as an exact source-neutral family for each named constituent.

Evidence

ComplexPortal:CPX-4262 Complex Portal entry for the E. coli K-12 LolCDE lipoprotein ABC transporter complex.
GO:0043190 Gene Ontology cellular-component parent term for ATP-binding cassette transporter complexes.
GO:0140306 Gene Ontology molecular-function term for lipoprotein releasing activity.
GO:0044874 Gene Ontology biological-process term for lipoprotein localization to outer membrane.
UniProtKB:P0ADC3 Reviewed E. coli K-12 LolC transmembrane protein entry.
UniProtKB:P75957 Reviewed E. coli K-12 LolD ATP-binding protein entry.
UniProtKB:P75958 Reviewed E. coli K-12 LolE transmembrane protein entry.
PDB:7MDY RCSB Protein Data Bank entry for a nucleotide-bound E. coli LolCDE electron-microscopy structure.
DOI:10.1038/s41467-021-24965-1 DOI for Sharma et al. 2021, Mechanism of LolCDE as a molecular extruder of bacterial triacylated lipoproteins.
PMID:10783239 PubMed identifier for Yakushi et al. 2000, A new ABC transporter mediating the detachment of lipid-modified proteins from membranes.
DOI:10.1038/35008635 DOI for Yakushi et al. 2000, A new ABC transporter mediating the detachment of lipid-modified proteins from membranes.
PMID:18634750 PubMed identifier for Moussatova et al. 2008, ATP-binding cassette transporters in Escherichia coli.
DOI:10.1016/j.bbamem.2008.06.009 DOI for Moussatova et al. 2008, ATP-binding cassette transporters in Escherichia coli.

Curation history

2026-10-02T09:04:13Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-10-02T09:05:36Z codex · EXPANDED_RECORD — Added ABC transporter parentage, LolC, LolD, and LolE component rows with E. coli K-12 reviewed UniProt examples, GO lipoprotein-releasing activity, a compact lipoprotein-release graph, CPX-4262 heterotetramer source composition, and a component-family grounding TODO.

Source: data/structures/other/lolcde_lipoprotein_abc_transporter_complex.yaml