Structure of dual-BON domain protein DolP identifies phospholipid binding as a new mechanism for protein localization
- University of Birmingham, United Kingdom
- Monash University, Australia
- National University of Singapore, Singapore
- IMB, University of Queensland, Australia
- University of Warwick, United Kingdom
- University of Alberta, Canada
- University of Queensland, Australia
Abstract
The Gram-negative outer membrane envelops the bacterium and functions as a permeability barrier against antibiotics, detergents and environmental stresses. Some virulence factors serve to maintain the integrity of the outer membrane, including DolP (formerly YraP) a protein of unresolved structure and function. Here we reveal DolP is a lipoprotein functionally conserved among Gram-negative bacteria and that loss of DolP increases membrane fluidity. We present the NMR solution structure for Escherichia coli DolP, which is composed of two BON domains that form an interconnected opposing pair. The C-terminal BON domain binds anionic phospholipids through an extensive membrane:protein interface. This interaction is essential for DolP function and is required for sub-cellular localization of the protein to the cell division site, providing evidence of subcellular localization of these phospholipids within the outer membrane. The structure of DolP provides a new target for developing therapies that disrupt the integrity of the bacterial cell envelope.
Data availability
Structural data have been deposited in PDB under the accession code 7A2D and the BMRB 19760.All data generated or analysed during this study are included in the manuscript and supporting files. We have supplied original images for Figures 1, 4, S1, S5, S9, and S10 in Additional Data File 1. We have also supplied raw data for Figure S10 in Additional Data File 2.
Article and author information
Author details
Jack Alfred Bryant
Funding
Biotechnology and Biological Sciences Research Council (BB/M00810X/1)
- Michael Overduin
- Ian R Henderson
Biotechnology and Biological Sciences Research Council (BB/L00335X/1)
- Michael Overduin
- Ian R Henderson
Biotechnology and Biological Sciences Research Council (BB/P009840/1)
- Timothy J Knowles
Natural Sciences and Engineering Research Council of Canada (RCP-12-002C)
- Michael Overduin
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2020, Bryant et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Structure of dual-BON domain protein DolP identifies phospholipid binding as a new mechanism for protein localization
eLife 9:e62614.
https://doi.org/10.7554/eLife.62614
Further reading
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- Biochemistry and Chemical Biology
- Microbiology and Infectious Disease
Teichoic acids (TA) are linear phospho-saccharidic polymers and important constituents of the cell envelope of Gram-positive bacteria, either bound to the peptidoglycan as wall teichoic acids (WTA) or to the membrane as lipoteichoic acids (LTA). The composition of TA varies greatly but the presence of both WTA and LTA is highly conserved, hinting at an underlying fundamental function that is distinct from their specific roles in diverse organisms. We report the observation of a periplasmic space in Streptococcus pneumoniae by cryo-electron microscopy of vitreous sections. The thickness and appearance of this region change upon deletion of genes involved in the attachment of TA, supporting their role in the maintenance of a periplasmic space in Gram-positive bacteria as a possible universal function. Consequences of these mutations were further examined by super-resolved microscopy, following metabolic labeling and fluorophore coupling by click chemistry. This novel labeling method also enabled in-gel analysis of cell fractions. With this approach, we were able to titrate the actual amount of TA per cell and to determine the ratio of WTA to LTA. In addition, we followed the change of TA length during growth phases, and discovered that a mutant devoid of LTA accumulates the membrane-bound polymerized TA precursor.
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- Biochemistry and Chemical Biology
- Computational and Systems Biology
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