Publication Date
4-12-2024
Journal
Science
DOI
10.1126/science.adl5899
PMID
38603484
PMCID
PMC11108255
PubMedCentral® Posted Date
5-21-2024
PubMedCentral® Full Text Version
Author MSS
Published Open-Access
yes
Keywords
Cryoelectron Microscopy, DNA, DNA Gyrase, DNA, Superhelical, Escherichia coli, Escherichia coli Proteins, Protein Domains
Abstract
DNA supercoiling must be precisely regulated by topoisomerases to prevent DNA entanglement. The interaction of type IIA DNA topoisomerases with two DNA molecules, enabling the transport of one duplex through the transient double-stranded break of the other, remains elusive owing to structures derived solely from single linear duplex DNAs lacking topological constraints. Using cryo–electron microscopy, we solved the structure of Escherichia coli DNA gyrase bound to a negatively supercoiled minicircle DNA. We show how DNA gyrase captures a DNA crossover, revealing both conserved molecular grooves that accommodate the DNA helices. Together with molecular tweezer experiments, the structure shows that the DNA crossover is of positive chirality, reconciling the binding step of gyrase-mediated DNA relaxation and supercoiling in a single structure.
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Biochemistry, Biophysics, and Structural Biology Commons, Biology Commons, Genetics Commons, Genomics Commons, Medical Genetics Commons, Medical Specialties Commons
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