Efficient and versatile one-step affinity purification of in vivo biotinylated proteins: Expression, characterization and structure analysis of recombinant human glutamate carboxypeptidase II

► A method of expression of biotinylated proteins in insect cells is described. ► Biotin protein ligase has to colocalize with the target for proper biotinylation. ► Tagged and biotinylated protein crystallizes after single step purification. ► Tag does not compromise enzymatic activity of the protein.