Products

Superresolution & Confocal Systems

  • Overview
  • MINFLUX
  • MIRAVA POLYSCOPE
  • INFINITY
  • FACILITY
  • STEDYCON
  • Software Overview
  • LiGHTBOX
  • STEDYCON smart control
  • iMSPECTOR

Superresolution & Confocal Modules

  • Overview
  • MINFLUX Module
  • MATRIX Detector
  • TIMEBOW Imaging
  • FLEXPOSURE Illumination
  • RAYSHAPE Mirror
  • TRUESHARP Deconvolution
  • EASY3D
  • RAINBOW Detection
  • STED Lasers
  • Autoalignment
  • Autofocus
  • Excitation Lasers
  • Accessories
  • Custom Solutions

Dyes & Labels

  • Overview
  • abberior STAR
  • abberior LIVE
  • abberior FLUX
  • abberior CAGE
  • abberior Supplies

Shop

  • Dyes by Product Name
  • Dyes by Technique
  • Dyes by Label
  • Mounting Medium
  • Cells and Nanoparticles

Applications

  • Overview
  • Biophysics
  • Cell Biology
  • Live Cell Imaging
  • Material Science
  • Membrane biology
  • Microbiology
  • Neurobiology
  • Physiology
  • Plant Science
  • Virology
  • Zoology

Company

  • People
  • Founders
  • Mission
  • Career
  • Vacancies
  • Locations

News & Events

  • News
  • Events
  • Webinars
  • Past Events

Expertise

  • Knowledge Base
  • FAQ Videos
  • FAQ
  • Publications
  • White Papers
  • Sample Gallery
  • Microscopy Tutorials
  • Webinar Recordings
  • Protocols
  • Support
  • Contact
  • Shop
  • Search
  • EN
    中文
    Language
@abberior.rocks
MENU Contact
MIRAVA POLYSCOPE – All in one and on for all: the perfect image
Science beyond Barriers

abberior dyes & labels

Microbiology

2023
International Journal of Molecular Sciences

StaR Is a Positive Regulator of Topoisomerase I Activity Involved in Supercoiling Maintenance in Streptococcus pneumoniae

Authors:

Antonio A de Vasconcelos Junior, Jose M Tirado-Vélez, Antonio J Martín-Galiano, Diego Megias, María-José Ferrándiz, Pablo Hernández, Mónica Amblar, Adela G de la Campa

Keywords:

DNA supercoiling; DNA topoisomerase I; DNA gyrase; supercoiling regulation; supercoiling homeostasis; nucleoid-associated proteins; topsoisomerase regulator; StaR

Abstract:

The DNA topoisomerases gyrase and topoisomerase I as well as the nucleoid-associated protein HU maintain supercoiling levels in Streptococcus pneumoniae, a main human pathogen. Here, we characterized, for the first time, a topoisomerase I regulator protein (StaR). In the presence of sub-inhibitory novobiocin concentrations, which inhibit gyrase activity, higher doubling times were observed in a strain lacking staR, and in two strains in which StaR was over-expressed either under the control of the ZnSO4-inducible PZn promoter (strain ΔstaRPZnstaR) or of the maltose-inducible PMal promoter (strain ΔstaRpLS1ROMstaR). These results suggest that StaR has a direct role in novobiocin susceptibility and that the StaR level needs to be maintained within a narrow range. Treatment of ΔstaRPZnstaR with inhibitory novobiocin concentrations resulted in a change of the negative DNA supercoiling density (σ) in vivo, which was higher in the absence of StaR (σ = -0.049) than when StaR was overproduced (σ = -0.045). We have located this protein in the nucleoid by using super-resolution confocal microscopy. Through in vitro activity assays, we demonstrated that StaR stimulates TopoI relaxation activity, while it has no effect on gyrase activity. Interaction between TopoI and StaR was detected both in vitro and in vivo by co-immunoprecipitation. No alteration of the transcriptome was associated with StaR amount variation. The results suggest that StaR is a new streptococcal nucleoid-associated protein that activates topoisomerase I activity by direct protein-protein interaction.

< Back to publications
Full article >
linkedin facebook bluesky twitter Instagram

World+49 551 9995 4010USA+1 301 661 0078

© 2025 abberior

Superresolution & Confocal Systems

  • Overview
  • MINFLUX
  • MIRAVA POLYSCOPE
  • INFINITY
  • FACILITY
  • STEDYCON
  • Software Overview
  • LiGHTBOX
  • STEDYCON smart control
  • iMSPECTOR

Superresolution & Confocal Modules

  • Overview
  • MINFLUX Module
  • MATRIX Detector
  • TIMEBOW Imaging
  • FLEXPOSURE Illumination
  • RAYSHAPE Mirror
  • TRUESHARP Deconvolution
  • EASY3D
  • RAINBOW Detection
  • STED Lasers
  • Autoalignment
  • Autofocus
  • Excitation Lasers
  • Accessories
  • Custom Solutions

Dyes & Labels

  • Overview
  • abberior STAR
  • abberior LIVE
  • abberior FLUX
  • abberior CAGE
  • abberior Supplies

Shop

  • Dyes by Product Name
  • Dyes by Technique
  • Dyes by Label
  • Mounting Medium
  • Cells and Nanoparticles

Applications

  • Overview
  • Biophysics
  • Cell Biology
  • Live Cell Imaging
  • Material Science
  • Membrane biology
  • Microbiology
  • Neurobiology
  • Physiology
  • Plant Science
  • Virology
  • Zoology

Company

  • People
  • Founders
  • Mission
  • Career
  • Vacancies
  • Locations

News & Events

  • News
  • Events
  • Webinars
  • Past Events

Expertise

  • Knowledge Base
  • FAQ Videos
  • FAQ
  • Publications
  • White Papers
  • Sample Gallery
  • Microscopy Tutorials
  • Webinar Recordings
  • Protocols
abberior instruments GmbH:
  • Imprint
  • Privacy Policy
  • Terms of Sale
abberior GmbH:
  • Imprint
  • Privacy Policy
  • Terms of Sale
Abberior Instruments America LLC:
  • Privacy Policy
  • Terms of use USA
  • contact
  • manuals
  • service
  • shop