Practice question

Tandem Affinity Purification employs TEV protease as a highly specific cleavage tool to release protein complexes between successive affinity steps. TAP tag typically contains Protein A IgG-binding domains, a TEV recognition site, and Calmodulin Binding Peptide. After first purification on IgG Sepharose, TEV protease, derived from Tobacco Etch Virus, recognizes consensus sequence ENLYFQG and cleaves specifically, liberating target complex under mild conditions. This enzymatic cleavage preserves native interactions and eliminates contaminants. Function is not tag synthesis, immobilization, or labeling, but precise sequence-specific proteolysis enabling second purification step.