Recombinant protein tagging is the genetic fusion of a peptide or protein sequence to a target protein, producing a polypeptide with an additional recognition or functional element. Tags can provide binding sites and can alter the solubility, yield, or folding of the fusion protein [1]. An affinity tag interacts with a corresponding ligand, allowing the tagged product to be selectively captured from a mixture [2]. Tag sequences can also encode epitopes, localization reporters, or elements that recruit cellular activities; their placement must preserve the reading frame of the target coding sequence [3]. In split-fluorescent-protein systems, a short fused fragment associates with a complementary fragment to assemble a fluorescent complex, linking detection to the presence of the tagged protein [4].
Protein Interaction Studies and Fluorescence Analysis·Molecular Biology·Biochemistry, Genetics and Molecular Biology·Life Sciences