Basis for the discrimination of supercoil handedness during DNA cleavage by human and bacterial type II topoisomerases.

Autor:	Jian JY; Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA., McCarty KD; Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA., Byl JAW; Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA., Guengerich FP; Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA., Neuman KC; Laboratory of Single Molecule Biophysics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20982, USA., Osheroff N; Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.; Department of Medicine (Hematology/Oncology), Vanderbilt University School of Medicine, Nashville, TN 37232, USA.; VA Tennessee Valley Healthcare System, Nashville, TN 37212, USA.
Jazyk:	angličtina
Zdroj:	Nucleic acids research [Nucleic Acids Res] 2023 May 08; Vol. 51 (8), pp. 3888-3902.
DOI:	10.1093/nar/gkad190
Abstrakt:	To perform double-stranded DNA passage, type II topoisomerases generate a covalent enzyme-cleaved DNA complex (i.e. cleavage complex). Although this complex is a requisite enzyme intermediate, it is also intrinsically dangerous to genomic stability. Consequently, cleavage complexes are the targets for several clinically relevant anticancer and antibacterial drugs. Human topoisomerase IIα and IIβ and bacterial gyrase maintain higher levels of cleavage complexes with negatively supercoiled over positively supercoiled DNA substrates. Conversely, bacterial topoisomerase IV is less able to distinguish DNA supercoil handedness. Despite the importance of supercoil geometry to the activities of type II topoisomerases, the basis for supercoil handedness recognition during DNA cleavage has not been characterized. Based on the results of benchtop and rapid-quench flow kinetics experiments, the forward rate of cleavage is the determining factor of how topoisomerase IIα/IIβ, gyrase and topoisomerase IV distinguish supercoil handedness in the absence or presence of anticancer/antibacterial drugs. In the presence of drugs, this ability can be enhanced by the formation of more stable cleavage complexes with negatively supercoiled DNA. Finally, rates of enzyme-mediated DNA ligation do not contribute to the recognition of DNA supercoil geometry during cleavage. Our results provide greater insight into how type II topoisomerases recognize their DNA substrates. (Published by Oxford University Press on behalf of Nucleic Acids Research 2023.)
Databáze:	MEDLINE
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