Dual function macrocyclase-peptidase involved in the biosynthesis of the highly toxic amanitin toxin family of macrocycles (PubMed:22202811, PubMed:28866879, PubMed:29051530). Cleaves peptide bonds on the C-terminal side of prolyl residues (PubMed:29051530). The enzyme first removes 10 residues from the N-terminus of a 35-residue substrate (PubMed:29051530). Conformational trapping of the 25 amino-acid peptide forces the enzyme to release this intermediate rather than proceed to macrocyclization (PubMed:29051530). The enzyme rebinds the 25 amino-acid peptide in a different conformation and catalyzes macrocyclization of the N-terminal eight residues (PubMed:28866879, PubMed:29051530). Hydrolysis of Pro-|-Xaa >> Ala-|-Xaa in oligopeptides. Monomer. Belongs to the peptidase S9A family. More to it - Issue 202 of April 2018