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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.

SUBMITTER: Basu A

PROVIDER: S-EPMC5660678 | biostudies-literature | 2012 Apr

REPOSITORIES: biostudies-literature

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ATP binding controls distinct structural transitions of Escherichia coli DNA gyrase in complex with DNA.

Basu Aakash A Schoeffler Allyn J AJ Berger James M JM Bryant Zev Z

Nature structural & molecular biology 20120408 5

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 t ...[more]

PMID: 22484318

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