UMMS Affiliation
Department of Biochemistry and Molecular Pharmacology; Cryo-EM Core Facility
Publication Date
2021-08-03
Document Type
Article
Disciplines
Amino Acids, Peptides, and Proteins | Bacteria | Bacteriology | Biochemistry, Biophysics, and Structural Biology | Lipids
Abstract
Lipoproteins are important for bacterial growth and antibiotic resistance. These proteins use lipid acyl chains attached to the N-terminal cysteine residue to anchor on the outer surface of cytoplasmic membrane. In Gram-negative bacteria, many lipoproteins are transported to the outer membrane (OM), a process dependent on the ATP-binding cassette (ABC) transporter LolCDE which extracts the OM-targeted lipoproteins from the cytoplasmic membrane. Lipid-anchored proteins pose a unique challenge for transport machinery as they have both hydrophobic lipid moieties and soluble protein component, and the underlying mechanism is poorly understood. Here we determined the cryo-EM structures of nanodisc-embedded LolCDE in the nucleotide-free and nucleotide-bound states at 3.8-A and 3.5-A resolution, respectively. The structural analyses, together with biochemical and mutagenesis studies, uncover how LolCDE recognizes its substrate by interacting with the lipid and N-terminal peptide moieties of the lipoprotein, and identify the amide-linked acyl chain as the key element for LolCDE interaction. Upon nucleotide binding, the transmembrane helices and the periplasmic domains of LolCDE undergo large-scale, asymmetric movements, resulting in extrusion of the captured lipoprotein. Comparison of LolCDE and MacB reveals the conserved mechanism of type VII ABC transporters and emphasizes the unique properties of LolCDE as a molecule extruder of triacylated lipoproteins.
Keywords
Bacterial structural biology, Cryoelectron microscopy
Rights and Permissions
Copyright © The Author(s) 2021. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
DOI of Published Version
10.1038/s41467-021-24965-1
Source
Sharma S, Zhou R, Wan L, Feng S, Song K, Xu C, Li Y, Liao M. Mechanism of LolCDE as a molecular extruder of bacterial triacylated lipoproteins. Nat Commun. 2021 Aug 3;12(1):4687. doi: 10.1038/s41467-021-24965-1. PMID: 34344901; PMCID: PMC8333309. Link to article on publisher's site
Journal/Book/Conference Title
Nature communications
Related Resources
PubMed ID
34344901
Repository Citation
Sharma S, Zhou R, Wan L, Feng S, Song K, Xu C, Li Y, Liao M. (2021). Mechanism of LolCDE as a molecular extruder of bacterial triacylated lipoproteins. Open Access Publications by UMass Chan Authors. https://doi.org/10.1038/s41467-021-24965-1. Retrieved from https://escholarship.umassmed.edu/oapubs/4903
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Included in
Amino Acids, Peptides, and Proteins Commons, Bacteria Commons, Bacteriology Commons, Biochemistry, Biophysics, and Structural Biology Commons, Lipids Commons