The Gateway® Nova pET-58-DEST™ vector is designed to create expression clones (pEXPR) that are fused to N-Terminal His•Tag® and Nus•Tag™ coding sequences and a Thrombin cleavage site. The Nus•Tag fusion is included to enhance the solubility of the fusion protein. If the pENTR clone lacks a stop codon and is appropriately designed for a C-terminal fusion, the target in the recombinant pEXPR clone will also be fused to a C-Terminal S•Tag™ coding sequence. The STag sequence allows quantification of the fusion protein using the FRETWorks™ assay (Cat. No 70724). The tag can also be used for purification, if a protease cleavage site is positioned upstream of the tag, and for detection.