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Photoaffinity Capture Compounds to Profile the Magic Spot Nucleotide Interactomes
Thomas M Haas1, Benoît-Joseph Laventie2, Simon Lagies1
1Institute of Organic Chemistry, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104, Freiburg im Breisgau, Germany.
Angewandte Chemie (International Ed. in English)
|March 16, 2022
Summary
Magic Spot Nucleotides (MSN) regulate bacterial stringent responses for survival. This study identified new MSN targets and found pppGpp inhibits ApaH, a key enzyme in bacterial stress adaptation.
Area of Science:
- Microbiology
- Chemical Biology
- Biochemistry
Background:
- The stringent response is a critical bacterial survival mechanism during stress.
- Understanding this response is vital for developing new antibiotics.
- Magic Spot Nucleotides (MSN) are key regulators of the stringent response.
Purpose of the Study:
- To delineate the Magic Spot Nucleotide (MSN) interactome in *Escherichia coli* and *Salmonella typhimurium*.
- To identify novel MSN targets using chemical proteomics.
- To investigate the interaction between MSNs and the ApaH enzyme.
Main Methods:
- Utilized trifunctional photoaffinity capture compounds to probe MSN interactions.
- Developed MSN probes with diverse phosphorylation patterns (pppGpp, ppGpp, pGpp).
- Employed chemical proteomics to analyze cytosolic and membrane fractions.
Main Results:
- Identified novel putative MSN receptors in both *E. coli* and *S. typhimurium*.
- Discovered that pppGpp potently inhibits the non-Nudix hydrolase ApaH.
- Demonstrated that ApaH converts pppGpp to pGpp.
Conclusions:
- The study provides a comprehensive MSN interactome map for key bacterial species.
- New insights into the regulation of bacterial stress response and potential antibiotic targets.
- The developed MSN probes are valuable tools for future interactome studies across bacterial species.
