Bacterium core enzymes have been easily identified, isolated and released using a glass resin and a 'bait' protein.   

By refining the known FlAsH probe system - a glass resin with a fluorescent dye immobilised on it, Uljana Mayer at the Pacific Northwest National Laboratory, US, and colleagues have been able to identify partners in protein-protein interactions.   

Mayer's method involves a protein tagged with a tetracysteine group - the bait. This is used to pull a RNA polymerase core enzyme from the bacterium Shewanella oneidensis.   

The tag holds the protein in place on the modified resin. Once it has been pulled out of the cell, and bound to the bait, the RNA polymerase core enzyme complex can be released in a single simple step. 

Protein-protein interactions are used by cells to react to external stresses. Mayer's work will add to the understanding of these interactions by identifying the complexes that arise from them. 'The rapid isolation of protein complexes is critical (for) establishing protein interactions,' she said.   

Michael Spencelayh