Structural, mechanistic and physiological insights into phospholipase A-mediated membrane phospholipid degradation in Pseudomonas aeruginosa
- Heinrich Heine University Düsseldorf, Germany
- Forschungszentrum Jülich GmbH, Germany
- University of Bonn, Germany
- Harvard Medical School, United States
- Helmholtz Centre for Infection Research, Germany
Abstract
Cells steadily adapt their membrane glycerophospholipid (GPL) composition to changing environmental and developmental conditions. While the regulation of membrane homeostasis via GPL synthesis in bacteria has been studied in detail, the mechanisms underlying the controlled degradation of endogenous GPLs remain unknown. Thus far, the function of intracellular phospholipases A (PLAs) in GPL remodeling (Lands cycle) in bacteria is not clearly established. Here, we identified the first cytoplasmic membrane-bound phospholipase A1 (PlaF) from Pseudomonas aeruginosa, which might be involved in the Lands cycle. PlaF is an important virulence factor, as the P. aeruginosa ΔplaF mutant showed strongly attenuated virulence in Galleria mellonella and macrophages. We present a 2.0-Å-resolution crystal structure of PlaF, the first structure that reveals homodimerization of a single-pass transmembrane (TM) full-length protein. PlaF dimerization, mediated solely through the intermolecular interactions of TM and juxtamembrane regions, inhibits its activity. The dimerization site and the catalytic sites are linked by an intricate ligand-mediated interaction network, which might explain the product (fatty acid) feedback inhibition observed with the purified PlaF protein. We used molecular dynamics simulations and configurational free energy computations to suggest a model of PlaF activation through a coupled monomerization and tilting of the monomer in the membrane, which constrains the active site cavity into contact with the GPL substrates. Thus, these data show the importance of the PlaF mediated GPL remodeling pathway for virulence and could pave the way for the development of novel therapeutics targeting PlaF.
Data availability
Diffraction data have been deposited in PDB under the accession code 6I8W.All data generated or analysed during this study are included in the manuscript and supporting file.Sequencing data are embedded in Fig. S1b.Source Data file "Table S1 - lipidome" has been provided for Figure 2. It contains the numerical data used to generate the figure 2c.Source data used to calculate the potentials of mean force and their corresponding simulation trajectory files shown in figure 7 and figure 7-supplementary figure 1 are accessible at the DSpace instance researchdata.hhu.de under DOI: 10.25838/d5p-31.
Article and author information
Author details
Funding
Deutsche Forschungsgemeinschaft (267205415)
- Holger Gohlke
- Karl Erich-Jäger
- Filip Kovacic
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2022, Bleffert 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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Structural, mechanistic and physiological insights into phospholipase A-mediated membrane phospholipid degradation in Pseudomonas aeruginosa
eLife 11:e72824.
https://doi.org/10.7554/eLife.72824
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