2kmt

Publication Abstract from PubMed

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.

Structural and thermodynamic characterization of Vibrio fischeri CcdB.,De Jonge N, Hohlweg W, Garcia-Pino A, Respondek M, Buts L, Haesaerts S, Lah J, Zangger K, Loris R J Biol Chem. 2010 Feb 19;285(8):5606-13. Epub 2009 Dec 2. PMID:19959472^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.