Rxivist logo

Faster diffusive dynamics of histone-like nucleoid structuring proteins in live bacteria caused by silver ions

By Asmaa A. Sadoon, Prabhat Khadka, Jack Freeland, Ravi Kumar Gundampati, Ryan Manso, Mason Ruiz, Venkata R. Krishnamurthi, Suresh Kumar Thallapuranam, Jingyi Chen, Yong Wang

Posted 30 Sep 2019
bioRxiv DOI: 10.1101/776229 (published DOI: 10.1128/AEM.02479-19)

The antimicrobial activity and mechanism of silver ions (Ag+) have gained broad attention in recent years. However, dynamic studies are rare in this field. Here, we report our measurement of the effects of Ag+ ions on the dynamics of histone-like nucleoid structuring (H-NS) proteins in live bacteria using single-particle tracking photoactivated localization microscopy (sptPALM). It was found that treating the bacteria with Ag+ ions led to faster diffusive dynamics of H-NS proteins. Several techniques were used to understand the mechanism of the observed faster dynamics. Electrophoretic mobility shift assay on purified H-NS proteins indicated that Ag+ ions weaken the binding between H-NS proteins and DNA. Isothermal titration calorimetry confirmed that DNA and Ag+ ions interact directly. Our recently developed sensing method based on bent DNA suggested that Ag+ ions caused dehybridization of double-stranded DNA (i.e., dissociation into single strands). These evidences led us to a plausible mechanism for the observed faster dynamics of H-NS proteins in live bacteria when subjected to Ag+ ions: Ag+-induced DNA dehybridization weakens the binding between H-NS proteins and DNA. This work highlighted the importance of dynamic study of single proteins in the live cells for understanding the functions of antimicrobial agents to the bacteria.

Download data

  • Downloaded 248 times
  • Download rankings, all-time:
    • Site-wide: 119,471
    • In biophysics: 4,582
  • Year to date:
    • Site-wide: 153,509
  • Since beginning of last month:
    • Site-wide: 149,745

Altmetric data

Downloads over time

Distribution of downloads per paper, site-wide