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Using Microtiter Dish Radiolabeling for Multiple In Vivo Measurements Of Escherichia coli (p)ppGpp Followed by Thin Layer Chromatography
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Using Microtiter Dish Radiolabeling for Multiple In Vivo Measurements Of Escherichia coli (p)ppGpp Followed by Thin Layer Chromatography

Published on: June 4, 2019

Different effects of ppGpp on Escherichia coli DNA replication in vivo and in vitro

Monika Maciąg-Dorszyńska1, Agnieszka Szalewska-Pałasz, Grzegorz Węgrzyn

  • 1Department of Molecular Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland.

FEBS Open Bio
|June 18, 2013
PubMed

Insights

Guanosine tetraphosphate (ppGpp) inhibits Escherichia coli DNA replication in vitro, potentially by affecting DnaG primase. However, this inhibition is not observed in E. coli cells, suggesting a masked effect.

Area of Science:

  • Molecular Biology
  • Microbiology
  • Biochemistry

Background:

  • Guanosine tetraphosphate (ppGpp) is a key regulator of bacterial responses to stress.
  • ppGpp is known to affect various cellular processes, including DNA replication.

Purpose of the Study:

  • To investigate the in vitro effect of ppGpp on Escherichia coli DNA replication.
  • To reconcile the in vitro findings with the lack of observed inhibition in vivo.

Main Methods:

  • In vitro assays measuring DNA replication.
  • Analysis of DNA synthesis in E. coli cells under stringent conditions.

Main Results:

  • ppGpp demonstrated inhibitory effects on E. coli DNA replication in vitro.
  • No rapid inhibition of DNA synthesis was detected in E. coli cells despite increased ppGpp levels.
  • The DnaG primase activity is a potential target for ppGpp inhibition.

Conclusions:

  • The in vitro inhibition of DNA replication by ppGpp is likely mediated through DnaG primase.
  • The absence of rapid inhibition in E. coli cells suggests that ppGpp's effect on DnaG may be masked in vivo.
  • This masking mechanism could explain discrepancies between E. coli and Bacillus subtilis regarding ppGpp's role in DNA replication.
Keywords:
DNA replicationGuanosine tetraphosphate (ppGpp)In vitro DNA synthesisStringent responseppGpp, guanosine tetraphosphatepppGpp, guanosine pentaphosphate.

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