Structural highlights
Function
POPB_GALM3 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).[1] [2] [3]
Publication Abstract from PubMed
Peptide macrocycles are promising therapeutic molecules because they are protease resistant, structurally rigid, membrane permeable, and capable of modulating protein-protein interactions. Here, we report the characterization of the dual function macrocyclase-peptidase enzyme involved in the biosynthesis of the highly toxic amanitin toxin family of macrocycles. The enzyme first removes 10 residues from the N-terminus of a 35-residue substrate. Conformational trapping of the 25 amino-acid peptide forces the enzyme to release this intermediate rather than proceed to macrocyclization. The enzyme rebinds the 25 amino-acid peptide in a different conformation and catalyzes macrocyclization of the N-terminal eight residues. Structures of the enzyme bound to both substrates and biophysical analysis characterize the different binding modes rationalizing the mechanism. Using these insights simpler substrates with only five C-terminal residues were designed, allowing the enzyme to be more effectively exploited in biotechnology.
Characterization of a dual function macrocyclase enables design and use of efficient macrocyclization substrates.,Czekster CM, Ludewig H, McMahon SA, Naismith JH Nat Commun. 2017 Oct 19;8(1):1045. doi: 10.1038/s41467-017-00862-4. PMID:29051530[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Luo H, Hallen-Adams HE, Scott-Craig JS, Walton JD. Ribosomal biosynthesis of α-amanitin in Galerina marginata. Fungal Genet Biol. 2012 Feb;49(2):123-9. PMID:22202811 doi:10.1016/j.fgb.2011.12.005
- ↑ Sgambelluri RM, Smith MO, Walton JD. Versatility of Prolyl Oligopeptidase B in Peptide Macrocyclization. ACS Synth Biol. 2018 Jan 19;7(1):145-152. PMID:28866879 doi:10.1021/acssynbio.7b00264
- ↑ Czekster CM, Ludewig H, McMahon SA, Naismith JH. Characterization of a dual function macrocyclase enables design and use of efficient macrocyclization substrates. Nat Commun. 2017 Oct 19;8(1):1045. doi: 10.1038/s41467-017-00862-4. PMID:29051530 doi:http://dx.doi.org/10.1038/s41467-017-00862-4
- ↑ Czekster CM, Ludewig H, McMahon SA, Naismith JH. Characterization of a dual function macrocyclase enables design and use of efficient macrocyclization substrates. Nat Commun. 2017 Oct 19;8(1):1045. doi: 10.1038/s41467-017-00862-4. PMID:29051530 doi:http://dx.doi.org/10.1038/s41467-017-00862-4
