Related Experiment Video
Updated: Oct 26, 2025
06:30
Using Microtiter Dish Radiolabeling for Multiple In Vivo Measurements Of Escherichia coli pppGpp Followed by Thin Layer Chromatography
Published on: June 4, 2019
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Two P or Not Two P: Understanding Regulation by the Bacterial Second Messengers (p)ppGpp
Gert Bange1,2,3, Ditlev E Brodersen4, Anastasia Liuzzi4
1SYNMIKRO Research Center, Philipps-University Marburg, 35043 Marburg, Germany;
Annual Review of Microbiology
|August 3, 2021
Summary
Bacteria adapt to stress using the stringent response, involving (p)ppGpp alarmones synthesized or degraded by RSH enzymes. These molecules regulate cellular effectors, impacting bacterial physiology differently across species.
Area of Science:
- Microbiology
- Molecular Biology
- Biochemistry
Background:
- Bacteria activate the stringent response under stress and nutrient starvation.
- This response involves RelA/SpoT homolog (RSH) proteins synthesizing hyperphosphorylated guanine nucleotides, (p)ppGpp.
- RSH enzymes can also degrade (p)ppGpp, with single-domain enzymes performing synthesis or hydrolysis.
Purpose of the Study:
- To provide an overview of (p)ppGpp metabolism.
- To focus on the functional and structural aspects of enzymes involved in (p)ppGpp synthesis and degradation.
- To discuss recent findings on alarmone-regulated cellular effectors.
Main Methods:
- Literature review of bacterial stringent response.
- Analysis of RSH protein superfamily structure and function.
- Examination of (p)ppGpp effector interactions and regulation.
Main Results:
- The stringent response is a key bacterial adaptation mechanism.
- (p)ppGpp alarmones are central to this response, produced and degraded by RSH enzymes.
- Downstream effectors of (p)ppGpp reveal conserved and distinct regulatory strategies in gram-negative and gram-positive bacteria.
Conclusions:
- RSH enzymes and (p)ppGpp are critical for bacterial stress adaptation.
- Understanding (p)ppGpp metabolism and its effectors provides insights into bacterial physiology.
- Comparative analysis highlights evolutionary differences in stringent response pathways.
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