Format

Send to

Choose Destination
See comment in PubMed Commons below
J Mol Biol. 1993 Dec 5;234(3):534-41.

The F plasmid CcdB protein induces efficient ATP-dependent DNA cleavage by gyrase.

Author information

  • 1Département de Biologie Moléculaire, Université Libre de Bruxelles, Rhode Saint Genèse, Belgium.

Abstract

DNA topoisomerases perform essential roles in DNA replication, gene transcription, and chromosome segregation. Recently, we identified a new type of topoisomerase II poison: the CcdB protein of plasmid F. When its action is not prevented by CcdA protein, the CcdB protein is a potent cytotoxin. In this paper, using purified CcdB, CcdA and gyrase, we show that CcdB protein efficiently traps gyrase in a cleavable complex. The CcdA protein not only prevents the gyrase poisoning activity of CcdB but also reverses its effect on gyrase. The mechanism by which the CcdB protein induces DNA strand breakage is closely related to the action of quinolone antibiotics. However, the ATP dependence of the CcdB cleavage process differentiates the CcdB mechanism from quinolone-dependent reactions because the quinolone antibiotics stimulate efficient DNA breakage, whether or not ATP is present. We previously showed that bacteria resistant to quinolone antibiotics are sensitive to CcdB and vice versa. Elucidation of the mechanism of action of CcdB protein may permit the design of drugs targeting gyrase so as to take advantage of this new poisoning mechanism.

PMID:
8254658
DOI:
10.1006/jmbi.1993.1609
[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Support Center