Fusion proteins

Joining two coding sequences in-frame within one recombinant gene produces a fusion protein: a single chain carrying amino acid sequences from two distinct proteins. Biotechnologists use the trick constantly: affinity tags fused to a target protein simplify purification, signal peptides drive secretion from cells, and reporter fusions reveal where proteins go. Industrial enzyme and therapeutic protein production leans on these constructs. Design must keep both parts folding correctly, since a tag that distorts the active domain ruins the product. Cleavable linkers let manufacturers cut the tag away after purification.