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Conformational Changes and Membrane Interaction of the Bacterial Phospholipase, ExoU: Characterization by Site-Directed Spin Labeling. Cell Biochem Biophys 2019 Mar;77(1):79-87

Date

07/27/2018

Pubmed ID

30047043

Pubmed Central ID

PMC6347562

DOI

10.1007/s12013-018-0851-8

Scopus ID

2-s2.0-85050694302 (requires institutional sign-in at Scopus site)   6 Citations

Abstract

Numerous pathogenic bacteria produce proteins evolved to facilitate their survival and dissemination by modifying the host environment. These proteins, termed effectors, often play a significant role in determining the virulence of the infection. Consequently, bacterial effectors constitute an important class of targets for the development of novel antibiotics. ExoU is a potent phospholipase effector produced by the opportunistic pathogen Pseudomonas aeruginosa. Previous studies have established that the phospholipase activity of ExoU requires non-covalent interaction with ubiquitin, however the molecular details of the mechanism of activation and the manner in which ExoU associates with a target lipid bilayer are not understood. In this review we describe our recent studies using site-directed spin labeling (SDSL) and EPR spectroscopy to elucidate the conformational changes and membrane interactions that accompany activation of ExoU. We find that ubiquitin binding and membrane interaction act synergistically to produce structural transitions that occur upon ExoU activation, and that the C-terminal four-helix bundle of ExoU functions as a phospholipid-binding domain, facilitating the association of ExoU with the membrane surface.

Author List

Feix JB, Kohn S, Tessmer MH, Anderson DM, Frank DW

Authors

Jimmy B. Feix PhD Professor in the Biophysics department at Medical College of Wisconsin
Dara W. Frank PhD Professor in the Microbiology and Immunology department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Bacterial Proteins
Electron Spin Resonance Spectroscopy
Liposomes
Phospholipases
Protein Binding
Pseudomonas aeruginosa
Spin Labels
Ubiquitin