Repurposing Proximity-Dependent Protein Labeling (BioID2) for Protein Interaction Mapping in E. coli.

Area of Science:

• Molecular Biology
• Biochemistry
• Systems Biology

Background:

• Protein-protein interactions are crucial for cellular functions.
• Proximity-dependent labeling methods, like BioID2, reveal these interactions in vivo.
• Adapting BioID2 for E. coli requires specific optimization.

Purpose of the Study:

• To develop and present a BioID2 toolkit tailored for E. coli.
• To demonstrate the utility of this toolkit using the chemotaxis protein CheA.
• To establish a methodology for identifying protein interaction networks in E. coli.

Main Methods:

• Constructed plasmids with BioID2 fused to target proteins (e.g., CheA) at N or C termini.
• Optimized fusion constructs with an 8×GGS linker for expression in E. coli.
• Developed protocols for protein expression, in vivo biotinylation, and analysis of biotinylated interactors.

Main Results:

• Successfully created and verified CheA-BioID2 fusion proteins in E. coli.
• Demonstrated in vivo biotinylation of proteins in proximity to CheA-BioID2.
• Established a workflow for capturing and identifying biotinylated protein interactors.

Conclusions:

• The developed BioID2 toolkit is effective for studying protein-protein interactions in E. coli.
• This methodology provides a valuable resource for mapping interaction networks in bacterial systems.
• The toolkit enables the discovery of novel protein interactions relevant to biological mechanisms.