pTYB2 is an E. coli cloning and expression vector (7474 bp) used in the IMPACT™ Kit (NEB #E6901) which allows the overexpression of a target protein as a fusion to a self-cleavable affinity tag (1,2). This C-terminal fusion vector is designed for the in-frame insertion of a target gene into the polylinker upstream of an intein tag (the Sce VMA intein/chitin binding domain, 55 kDa) (1,2). This results in the fusion of the C-terminus of the target protein to the N-terminus of the intein tag. Thiol-induced self-cleavage of the intein releases the target protein from the chitin-bound intein tag, resulting in a single column purification of the target protein.

For fusion of the N-terminus of the target protein to the intein tag, use pTYB21 (NEB #N6709) or pTYB22 (NEB #N6710). This vector can be used in conjuction with pTYB22 (NEB #N6710) to test which fusion constructin (N-terminal or C-terminal) maximizes the expression and yield of a target protein (3).