Solution structures of DNA-bound gyrase

Nicole M. Baker, Steven Weigand, Sarah Maar-Mathias, Alfonso Mondragón*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

26 Scopus citations

Abstract

The DNA gyrase negative supercoiling mechanism involves the assembly of a large gyrase/DNA complex and conformational rearrangements coupled to ATP hydrolysis. To establish the complex arrangement that directs the reaction towards negative supercoiling, bacterial gyrase complexes bound to 137- or 217-bp DNA fragments representing the starting conformational state of the catalytic cycle were characterized by sedimentation velocity and small-angle X-ray scattering (SAXS) experiments. The experiments revealed elongated complexes with hydrodynamic radii of 70-80. Molecular envelopes calculated from these SAXS data show 2-fold symmetric molecules with the C-terminal domain (CTD) of the A subunit and the ATPase domain of the B subunit at opposite ends of the complexes. The proposed gyrase model, with the DNA binding along the sides of the molecule and wrapping around the CTDs located near the exit gate of the protein, adds new information on the mechanism of DNA negative supercoiling.

Original languageEnglish (US)
Pages (from-to)755-766
Number of pages12
JournalNucleic acids research
Volume39
Issue number2
DOIs
StatePublished - Jan 2011

ASJC Scopus subject areas

  • Genetics

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