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Single-molecule fluorescence microscopy reveals modulation of DNA polymerase IV-binding lifetimes by UmuD (K97A) and UmuD¿

Journal Article


Abstract


  • 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 UmuDʹ 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, UmuDʹ, which accumulates in DNA-damaged cells, reduces binding. The results provide additional support for a model in which UmuD and UmuDʹ directly modulate pol IV-binding to the nucleoid.

Publication Date


  • 2021

Citation


  • Henrikus, S. S., van Oijen, A. M., & Robinson, A. (2021). Single-molecule fluorescence microscopy reveals modulation of DNA polymerase IV-binding lifetimes by UmuD (K97A) and UmuD¿. Current Genetics, 67(2), 295-303. doi:10.1007/s00294-020-01134-3

Scopus Eid


  • 2-s2.0-85098485670

Start Page


  • 295

End Page


  • 303

Volume


  • 67

Issue


  • 2

Abstract


  • 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 UmuDʹ 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, UmuDʹ, which accumulates in DNA-damaged cells, reduces binding. The results provide additional support for a model in which UmuD and UmuDʹ directly modulate pol IV-binding to the nucleoid.

Publication Date


  • 2021

Citation


  • Henrikus, S. S., van Oijen, A. M., & Robinson, A. (2021). Single-molecule fluorescence microscopy reveals modulation of DNA polymerase IV-binding lifetimes by UmuD (K97A) and UmuD¿. Current Genetics, 67(2), 295-303. doi:10.1007/s00294-020-01134-3

Scopus Eid


  • 2-s2.0-85098485670

Start Page


  • 295

End Page


  • 303

Volume


  • 67

Issue


  • 2