Abstract

The opportunistic pathogen Pseudomonas aeruginosa causes antibiotic resistant, nosocomial infections in immuno-compromised individuals, and is a high priority for antimicrobial development. Key to pathogenicity in P. aeruginosa are biofilm formation and virulence factor production. Both traits are controlled by the cell-to-cell communication process called quorum sensing (QS). QS involves the synthesis, release, and population-wide detection of signal molecules called autoinducers. We previously reported that activity of the RhlR QS transcription factor depends on a protein-protein interaction with the hydrolase, PqsE, and PqsE catalytic activity is dispensable for this interaction. Nonetheless, the PqsE-RhlR interaction could be disrupted by substitution of an active site glutamate residue with tryptophan (PqsE(E182W)). Here, we show that disruption of the PqsE-RhlR interaction via either the E182W change or alteration of PqsE surface residues that are essential for the interaction with RhlR, attenuates P. aeruginosa infection in a murine host. We use crystallography to characterize the conformational changes induced by the PqsE(E182W) substitution to define the mechanism underlying disruption of the PqsE-RhlR interaction. A loop rearrangement that repositions the E280 residue in PqsE(E182W) is responsible for the loss of interaction. We verify the implications garnered from the PqsE(E182W) structure using mutagenic, biochemical, and additional structural analyses. We present the next generation of molecules targeting the PqsE active site, including a structure of the tightest binding of these compounds, BB584, in complex with PqsE. The findings presented here provide insight for drug discovery against P. aeruginosa with PqsE as the target.

Competing Interest Statement

The authors have declared no competing interest.

Details

Title
The PqsE active site as a target for small molecule antimicrobial agents against Pseudomonas aeruginosa
Author
Taylor, Isabelle R; Jeffrey, Philip D; Moustafa, Dina A; Goldberg, Joanna B; Bassler, Bonnie L
University/institution
Cold Spring Harbor Laboratory Press
Section
New Results
Publication year
2022
Publication date
Apr 21, 2022
Publisher
Cold Spring Harbor Laboratory Press
ISSN
2692-8205
Source type
Working Paper
Language of publication
English
ProQuest document ID
2653042479
Copyright
© 2022. This article is published under http://creativecommons.org/licenses/by/4.0/ (“the License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.