Crystallization of CcdB in complex with a GyrA fragment.

TitleCrystallization of CcdB in complex with a GyrA fragment.
Publication TypeJournal Article
Year of Publication2004
AuthorsDao-Thi, M-H., L. Van Melderen, E. De Genst, L. Buts, A. Ranquin, L. Wyns, and R. Loris
JournalActa Crystallogr D Biol Crystallogr
IssuePt 6
Date Published2004 Jun
KeywordsBacterial Proteins, Bacterial Toxins, Cloning, Molecular, Crystallography, X-Ray, Dimerization, DNA Gyrase, Electrophoresis, Polyacrylamide Gel, Escherichia coli, F Factor, Plasmids, Protein Binding, Protein Structure, Tertiary, Surface Plasmon Resonance, X-Ray Diffraction

Plasmid addiction systems consist of a plasmid-encoded toxin-antidote pair that serves to stabilize low-copy-number plasmids in bacterial populations. CcdB, the toxin from the ccd system on the Escherichia coli F plasmid, acts as a gyrase poison. A 14 kDa fragment of gyrase, GyrA14, was found to bind to the toxin CcdB with an affinity of 1.75 x 10(-8) M. Crystals of the (GyrA14)(2) dimer in its free state belong to space group P4(3)2(1)2, with unit-cell parameters a = 86.4, c = 89.4 angstroms, and diffract to 2.4 angstroms. Crystals of the (GyrA14)(2)-(CcdB)(2) complex belong to space group P2(1)2(1)2(1), with a = 52.1, b = 83.3, c = 110.9 angstroms, and diffract to 2.8 angstroms resolution.

Alternate JournalActa Crystallogr. D Biol. Crystallogr.
PubMed ID15159578