The recent findings of Waldo et al. 1 demonstrate that the fusion of the green fluorescent protein (GFP) to insoluble proteins dramatically reduces its folding ability in prokaryotic cells.

The DD is a 12-kDa (107-amino-acid) tag based on a mutated FKBP protein. When a protein of interest is expressed as a fusion with the DD tag, it is destabilized and rapidly degraded in the cell by ...