Mechanochemical analysis of DNA gyrase using rotor bead tracking

Jeff Gore, Zev Bryant, Michael D. Stone, Marcelo Nöllmann, Nicholas R. Cozzarelli () and Carlos Bustamante ()
Additional contact information
Jeff Gore: University of California
Zev Bryant: University of California
Michael D. Stone: University of California
Marcelo Nöllmann: University of California
Nicholas R. Cozzarelli: University of California
Carlos Bustamante: University of California

Nature, 2006, vol. 439, issue 7072, 100-104

Abstract: Abstract DNA gyrase is a molecular machine that uses the energy of ATP hydrolysis to introduce essential negative supercoils into DNA1,2,3. The directionality of supercoiling is ensured by chiral wrapping of the DNA4,5 around a specialized domain6,7,8,9 of the enzyme before strand passage. Here we observe the activity of gyrase in real time by tracking the rotation of a submicrometre bead attached to the side of a stretched DNA molecule10. In the presence of gyrase and ATP, we observe bursts of rotation corresponding to the processive, stepwise introduction of negative supercoils in strict multiples of two11. Changes in DNA tension have no detectable effect on supercoiling velocity, but the enzyme becomes markedly less processive as tension is increased over a range of only a few tenths of piconewtons. This behaviour is quantitatively explained by a simple mechanochemical model in which processivity depends on a kinetic competition between dissociation and rapid, tension-sensitive DNA wrapping. In a high-resolution variant of our assay, we directly detect rotational pauses corresponding to two kinetic substeps: an ATP-independent step at the end of the reaction cycle, and an ATP-binding step in the middle of the cycle, subsequent to DNA wrapping.

Date: 2006
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.nature.com/articles/nature04319 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:439:y:2006:i:7072:d:10.1038_nature04319

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/nature04319

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().