Single-molecule fluorescence microscopy reveals modulation of DNA polymerase IV-binding lifetimes by UmuD (K97A) and UmuD'.
Sarah S HenrikusAntoine M van OijenAndrew RobinsonPublished in: Current genetics (2021)
DNA polymerase IV (pol IV) is expressed at increased levels in Escherichia coli cells that suffer DNA damage. In a recent live-cell single-molecule fluorescence microscopy study, we demonstrated that the formation of pol IV foci is strongly recB-dependent in cells treated with the DNA break-inducing antibiotic ciprofloxacin. The results of that study support a model in which pol IV acts to extend D-loop structures during recombinational repair of DNA double-strand breaks. In the present study, we extend upon this work, investigating the UmuD and UmuD' proteins as potential modulators of pol IV activity in ciprofloxacin-treated cells. We found that the non-cleavable mutant UmuD(K97A) promotes long-lived association of pol IV with the nucleoid, whereas its cleaved form, UmuD', which accumulates in DNA-damaged cells, reduces binding. The results provide additional support for a model in which UmuD and UmuD' directly modulate pol IV-binding to the nucleoid.
Keyphrases
- single molecule
- induced apoptosis
- living cells
- atomic force microscopy
- cell cycle arrest
- escherichia coli
- dna damage
- pseudomonas aeruginosa
- oxidative stress
- cell free
- cell death
- small molecule
- multidrug resistant
- high resolution
- pi k akt
- cystic fibrosis
- biofilm formation
- nucleic acid
- cell proliferation
- circulating tumor cells
- newly diagnosed
- klebsiella pneumoniae