Figure 1.

Autoprocessing activity of native and repurposed hedgehog domain, HhC. Precursor polypeptide is composed of substrate protein (blue) and HhC (green). Following peptide rearrangement at a conserved Gly-Cys to form an internal thioester intermediate, step 1, the two fragments split apart in step 2 through displacement by cholesterol in the native transformation, or by sterylated nucleic acid described herein. All catalytic activity resides in HhC.