Abstract
Branched Lipid II, required for the formation of indirectly crosslinked peptidoglycan, is generated by MurM, a protein essential for high-level penicillin resistance in the human pathogen Streptococcus pneumoniae. We have solved the X-ray crystal structure of Staphylococcus aureus FemX, an isofunctional homolog, and have used this as a template to generate a MurM homology model. Using this model, we perform molecular docking and molecular dynamics to examine the interaction of MurM with the phospholipid bilayer and the membrane-embedded Lipid II substrate. Our model suggests that MurM is associated with the major membrane phospholipid cardiolipin, and experimental evidence confirms that the activity of MurM is enhanced by this phospholipid and inhibited by its direct precursor phosphatidylglycerol. The spatial association of pneumococcal membrane phospholipids and their impact on MurM activity may therefore be critical to the final architecture of peptidoglycan and the expression of clinically relevant penicillin resistance in this pathogen.
Original language | English |
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Article number | 1 |
Pages (from-to) | 731-742.e6 |
Journal | Structure |
Volume | 29 |
Issue number | 7 |
Early online date | 18 Mar 2021 |
DOIs | |
Publication status | Published - 1 Jul 2021 |
Bibliographical note
NOTICE: this is the author’s version of a work that was accepted for publication in Structure. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Structure, 7:1, (2021) DOI: 10.1016/j.str.2021.03.001© 2021, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/
Funder
This research was supported in part by the Midlands Integrative Biosciences Training Partnership (MIBTP) BBSRC grant BB/J014532/1, and the Center for Doctoral Training in Theory and Modeling in Chemical Sciences (TMCS DTC) EPSRC grant EP/L015722/1, as well as MRC grants G1100127, G0400848, MR/N002679/1 and BBSRC grant BB/N003241/1.Keywords
- Streptococcus pneumoniae
- MurM
- penicillin resistance
- peptidoglycan
- indirect crosslinks
- lipid bilayer
- homology modeling
- molecular dynamics
- molecular docking
ASJC Scopus subject areas
- Molecular Biology