Cracking the code of cellular protein-protein interactions: Alphafold and whole-cell crosslinking to the rescue.

Integration of experimental and computational methods is crucial to better understanding protein-protein interactions (PPIs), ideally in their cellular context. In their recent work, Rappsilber and colleagues (O'Reilly et al, 2023) identified bacterial PPIs using an array of approaches. They combined whole-cell crosslinking, co-fractionation mass spectrometry, and open-source data mining with artificial intelligence (AI)-based structure prediction of PPIs in the well-studied organism Bacillus subtilis. This innovative approach reveals architectural knowledge for in-cell PPIs that are often lost upon cell lysis, making it applicable to genetically intractable organisms such as pathogenic bacteria.