Energetics of structural transitions of the addiction antitoxin MazE: is a programmed bacterial cell death dependent on the intrinsically flexible nature of the antitoxins?

TitleEnergetics of structural transitions of the addiction antitoxin MazE: is a programmed bacterial cell death dependent on the intrinsically flexible nature of the antitoxins?
Publication TypeJournal Article
Year of Publication2005
AuthorsLah, J., M. Simic, G. Vesnaver, I. Marianovsky, G. Glaser, H. Engelberg-Kulka, and R. Loris
JournalJ Biol Chem
Volume280
Issue17
Pagination17397-407
Date Published2005 Apr 29
ISSN0021-9258
KeywordsAntitoxins, Apoptosis, Calorimetry, Differential Scanning, Circular Dichroism, Crystallography, X-Ray, Dimerization, DNA-Binding Proteins, Endoribonucleases, Escherichia coli, Escherichia coli Proteins, Fluorometry, Hot Temperature, Hydrogen-Ion Concentration, Models, Molecular, Protein Conformation, Protein Folding, Protein Structure, Secondary, Spectrometry, Fluorescence, Spectrophotometry, Temperature, Thermodynamics, Ultraviolet Rays, Urea
Abstract

The Escherichia coli mazEF addiction module plays a crucial role in the cell death program that is triggered under various stress conditions. It codes for the toxin MazF and the antitoxin MazE, which interferes with the lethal action of the toxin. To better understand the role of various conformations of MazE in bacterial life, its order-disorder transitions were monitored by differential scanning calorimetry, spectropolarimetry, and fluorimetry. The changes in spectral and thermodynamic properties accompanying MazE dimer denaturation can be described in terms of a compensating reversible process of the partial folding of the unstructured C-terminal half (high mean net charge, low mean hydrophobicity) and monomerization coupled with the partial unfolding of the structured N-terminal half (low mean net charge, high mean hydrophobicity). At pH

DOI10.1074/jbc.M501128200
Alternate JournalJ. Biol. Chem.
PubMed ID15735309