Structural and thermodynamic characterization of Vibrio fischeri CcdB.

TitleStructural and thermodynamic characterization of Vibrio fischeri CcdB.
Publication TypeJournal Article
Year of Publication2010
AuthorsDe Jonge, N., W. Hohlweg, A. Garcia-Pino, M. Respondek, L. Buts, S. Haesaerts, J. Lah, K. Zangger, and R. Loris
JournalJ Biol Chem
Date Published2010 Feb 19
Type of Articleta
KeywordsAliivibrio fischeri, Bacterial Toxins, Hydrophobic and Hydrophilic Interactions, Nuclear Magnetic Resonance, Biomolecular, Protein Multimerization, Protein Structure, Quaternary, Protein Structure, Secondary, Thermodynamics

CcdB(Vfi) from Vibrio fischeri is a member of the CcdB family of toxins that poison covalent gyrase-DNA complexes. In solution CcdB(Vfi) is a dimer that unfolds to the corresponding monomeric components in a two-state fashion. In the unfolded state, the monomer retains a partial secondary structure. This observation correlates well with the crystal and NMR structures of the protein, which show a dimer with a hydrophobic core crossing the dimer interface. In contrast to its F plasmid homologue, CcdB(Vfi) possesses a rigid dimer interface, and the apparent relative rotations of the two subunits are due to structural plasticity of the monomer. CcdB(Vfi) shows a number of non-conservative substitutions compared with the F plasmid protein in both the CcdA and the gyrase binding sites. Although variation in the CcdA interaction site likely determines toxin-antitoxin specificity, substitutions in the gyrase-interacting region may have more profound functional implications.

Alternate JournalJ. Biol. Chem.
PubMed ID19959472
PubMed Central IDPMC2820787
Grant ListW 901-B12 / / Austrian Science Fund FWF / Austria