SlyD is a putative folding helper protein from the Escherichia coli cytosol, which consists of an N-terminal prolyl isomerase domain of the FKBP type and a presumably unstructured C-terminal tail. It is involved in the biosynthesis of the metal cluster in the [NiFe]-hydrogenase enzymes, and exhibits several activities including that of a peptidyl-prolyl isomerase. MW: 21 kDa (196 aa, 1-196 aa). Purity ≥95%