Structural basis of topoisomerase targeting by delafloxacin

Abstract Delafloxacin is a potent anionic fluoroquinolone approved for the treatment of respiratory infections that acts by trapping the DNA cleavage complexes of bacterial topoisomerase IV and gyrase. Its N-1-pyridinyl-, C-7-azetidinyl- and C-8-chlorine substituents confer enhanced antibiotic activ...

Full description

Saved in:
Bibliographic Details
Main Authors: Shabir Najmudin, Xiao-Su Pan, Beijia Wang, Lata Govada, Naomi E. Chayen, Noelia Rubio, Milo S. P. Shaffer, Henry S. Rzepa, L. Mark Fisher, Mark R. Sanderson
Format: Article
Language:English
Published: Nature Portfolio 2025-07-01
Series:Nature Communications
Online Access:https://doi.org/10.1038/s41467-025-60688-3
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849334472774778880
author Shabir Najmudin
Xiao-Su Pan
Beijia Wang
Lata Govada
Naomi E. Chayen
Noelia Rubio
Milo S. P. Shaffer
Henry S. Rzepa
L. Mark Fisher
Mark R. Sanderson
author_facet Shabir Najmudin
Xiao-Su Pan
Beijia Wang
Lata Govada
Naomi E. Chayen
Noelia Rubio
Milo S. P. Shaffer
Henry S. Rzepa
L. Mark Fisher
Mark R. Sanderson
author_sort Shabir Najmudin
collection DOAJ
description Abstract Delafloxacin is a potent anionic fluoroquinolone approved for the treatment of respiratory infections that acts by trapping the DNA cleavage complexes of bacterial topoisomerase IV and gyrase. Its N-1-pyridinyl-, C-7-azetidinyl- and C-8-chlorine substituents confer enhanced antibiotic activity against bacteria resistant to other fluoroquinolones, but its mode of action is unclear. Here we present the X-ray crystal structures of a delafloxacin-DNA cleavage complex obtained by co-crystallization with Streptococcus pneumoniae topo IV using a graphene nucleant and solved at 2.0 and 2.4 Å resolution. The two Mg2+-chelated delafloxacin molecules intercalated at the DNA cleavage site are bound in an unusual conformation involving interacting out-of-plane N-1-aromatic- and C-8-chlorine- substituents. The unprecedented resolution allows comprehensive imaging of water-metal ion links integrating enzyme and DNA through drug-bound and active-site Mg2+ ions plus the discovery of enzyme-bound K+ ions. Our studies on delafloxacin action suggest that intrinsic target affinity contributes to its activity against quinolone-resistant bacteria.
format Article
id doaj-art-9951fe05aa794aed88923fcaebffc981
institution Kabale University
issn 2041-1723
language English
publishDate 2025-07-01
publisher Nature Portfolio
record_format Article
series Nature Communications
spelling doaj-art-9951fe05aa794aed88923fcaebffc9812025-08-20T03:45:33ZengNature PortfolioNature Communications2041-17232025-07-0116111510.1038/s41467-025-60688-3Structural basis of topoisomerase targeting by delafloxacinShabir Najmudin0Xiao-Su Pan1Beijia Wang2Lata Govada3Naomi E. Chayen4Noelia Rubio5Milo S. P. Shaffer6Henry S. Rzepa7L. Mark Fisher8Mark R. Sanderson9Molecular and Cellular Sciences Section, Neuroscience and Cell Biology Research Institute, City St George’s, University of London, Cranmer TerraceMolecular and Cellular Sciences Section, Neuroscience and Cell Biology Research Institute, City St George’s, University of London, Cranmer TerraceDivision of Systems Medicine, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College LondonDivision of Systems Medicine, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College LondonDivision of Systems Medicine, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College LondonDepartments of Chemistry & Materials Science, Imperial College LondonDepartments of Chemistry & Materials Science, Imperial College LondonDepartment of Chemistry, Imperial College LondonMolecular and Cellular Sciences Section, Neuroscience and Cell Biology Research Institute, City St George’s, University of London, Cranmer TerraceMolecular and Cellular Sciences Section, Neuroscience and Cell Biology Research Institute, City St George’s, University of London, Cranmer TerraceAbstract Delafloxacin is a potent anionic fluoroquinolone approved for the treatment of respiratory infections that acts by trapping the DNA cleavage complexes of bacterial topoisomerase IV and gyrase. Its N-1-pyridinyl-, C-7-azetidinyl- and C-8-chlorine substituents confer enhanced antibiotic activity against bacteria resistant to other fluoroquinolones, but its mode of action is unclear. Here we present the X-ray crystal structures of a delafloxacin-DNA cleavage complex obtained by co-crystallization with Streptococcus pneumoniae topo IV using a graphene nucleant and solved at 2.0 and 2.4 Å resolution. The two Mg2+-chelated delafloxacin molecules intercalated at the DNA cleavage site are bound in an unusual conformation involving interacting out-of-plane N-1-aromatic- and C-8-chlorine- substituents. The unprecedented resolution allows comprehensive imaging of water-metal ion links integrating enzyme and DNA through drug-bound and active-site Mg2+ ions plus the discovery of enzyme-bound K+ ions. Our studies on delafloxacin action suggest that intrinsic target affinity contributes to its activity against quinolone-resistant bacteria.https://doi.org/10.1038/s41467-025-60688-3
spellingShingle Shabir Najmudin
Xiao-Su Pan
Beijia Wang
Lata Govada
Naomi E. Chayen
Noelia Rubio
Milo S. P. Shaffer
Henry S. Rzepa
L. Mark Fisher
Mark R. Sanderson
Structural basis of topoisomerase targeting by delafloxacin
Nature Communications
title Structural basis of topoisomerase targeting by delafloxacin
title_full Structural basis of topoisomerase targeting by delafloxacin
title_fullStr Structural basis of topoisomerase targeting by delafloxacin
title_full_unstemmed Structural basis of topoisomerase targeting by delafloxacin
title_short Structural basis of topoisomerase targeting by delafloxacin
title_sort structural basis of topoisomerase targeting by delafloxacin
url https://doi.org/10.1038/s41467-025-60688-3
work_keys_str_mv AT shabirnajmudin structuralbasisoftopoisomerasetargetingbydelafloxacin
AT xiaosupan structuralbasisoftopoisomerasetargetingbydelafloxacin
AT beijiawang structuralbasisoftopoisomerasetargetingbydelafloxacin
AT latagovada structuralbasisoftopoisomerasetargetingbydelafloxacin
AT naomiechayen structuralbasisoftopoisomerasetargetingbydelafloxacin
AT noeliarubio structuralbasisoftopoisomerasetargetingbydelafloxacin
AT milospshaffer structuralbasisoftopoisomerasetargetingbydelafloxacin
AT henrysrzepa structuralbasisoftopoisomerasetargetingbydelafloxacin
AT lmarkfisher structuralbasisoftopoisomerasetargetingbydelafloxacin
AT markrsanderson structuralbasisoftopoisomerasetargetingbydelafloxacin