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Title: Probing the role of the ATP-operated clamp in the strand-passage reaction of DNA gyrase
Authors: Tingey, Andrew P.
Maxwell, Anthony
First Published: 15-Oct-1996
Publisher: Oxford University Press (OUP)
Citation: Nucleic Acids Research, 1996, Vol. 24, No. 24 4868-4873.
Abstract: The high-resolution structure of the 43 kDa N-terminal fragment of the DNA gyrase B protein shows a large cavity within the protein dimer. The approximate size of this cavity is 20 Å , suggesting it could accommodate a DNA helix. Computer-modelling studies of this cavity suggest that it contains a constriction, reducing the width to ∼13 Å, principally caused by the side chain of Arg286. We have used site-directed mutagenesis to alter this residue to Gln. Gyrase bearing this mutation shows virtually no supercoiling activity and near normal relaxation and DNA cleavage activities. The mutated protein has ATPase activity which cannot be stimulated by DNA. These data support the proposed role of the 43 kDa domain as an ATP-operated clamp which binds DNA during the supercoiling cycle. The lack of DNA-dependent ATPase of the mutant may indicate that binding of DNA within the clamp is a prerequisite for stimulation of the ATPase activity
DOI Link: 10.1093/nar/24.24.4868
ISSN: 0305-1048
eISSN: 1362-4962
Version: Publisher Version
Status: Peer-reviewed
Type: Journal Article
Rights: Archived with reference to SHERPA/RoMEO and publisher website. Copyright 1996 Oxford University Press Version of record:
Appears in Collections:Published Articles, Dept. of Biochemistry

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