title: ATP binding controls distinct structural transitions of Escherichia coli DNA gyrase in complex with DNA.
abstract: DNA gyrase is a molecular motor that harnesses the free energy of ATP hydrolysis to introduce negative supercoils into DNA. A critical step in this reaction is the formation of a chiral DNA wrap. Here we observe gyrase structural dynamics using a single-molecule assay in which gyrase drives the processive, stepwise rotation of a nanosphere attached to the side of a stretched DNA molecule. Analysis of rotational pauses and measurements of DNA contraction reveal multiple ATP-modulated structural transitions. DNA wrapping is coordinated with the ATPase cycle and proceeds by way of an unanticipated structural intermediate that dominates the kinetics of supercoiling. Our findings reveal a conformational landscape of loosely coupled transitions funneling the motor toward productive energy transduction, a feature that may be common to the reaction cycles of other DNA and protein remodeling machines.
authors.affiliation: Department of Applied Physics, Stanford University, Stanford, California, USA.
authors.forename: Aakash
authors.initials: A
authors.lastname: Basu
authors.forename: Allyn J
authors.initials: AJ
authors.lastname: Schoeffler
authors.forename: James M
authors.initials: JM
authors.lastname: Berger
authors.forename: Zev
authors.initials: Z
authors.lastname: Bryant
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D027081:DNA Gyrase / Q000737:chemistry / Q000378:metabolism*; D004269:DNA, Bacterial / Q000737:chemistry / Q000378:metabolism*; D004278:DNA, Superhelical / Q000737:chemistry / Q000378:metabolism; D004926:Escherichia coli / Q000737:chemistry / Q000201:enzymology* / Q000378:metabolism; D007700:Kinetics; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D011487:Protein Conformation
chemical_list: D004269:DNA, Bacterial; D004278:DNA, Superhelical; D000255:Adenosine Triphosphate; D027081:DNA Gyrase