7M4S
Crystal structure of macrocyclase AMdnB from Anabaena sp. PCC 7120
Summary for 7M4S
| Entry DOI | 10.2210/pdb7m4s/pdb |
| Descriptor | AMdnB protein (2 entities in total) |
| Functional Keywords | natural products, ripps, macrocyclase, biosynthetic protein |
| Biological source | Nostoc sp. (strain PCC 7120 / SAG 25.82 / UTEX 2576) |
| Total number of polymer chains | 4 |
| Total formula weight | 165142.17 |
| Authors | Li, G.,Bruner, S.D. (deposition date: 2021-03-22, release date: 2021-11-03, Last modification date: 2024-10-23) |
| Primary citation | Li, G.,Patel, K.,Zhang, Y.,Pugmire, J.K.,Ding, Y.,Bruner, S.D. Structural and biochemical studies of an iterative ribosomal peptide macrocyclase. Proteins, 90:670-679, 2022 Cited by PubMed Abstract: Microviridins, tricyclic peptide natural products originally isolated from cyanobacteria, function as inhibitors of diverse serine-type proteases. Here we report the structure and biochemical characterization of AMdnB, a unique iterative macrocyclase involved in a microviridin biosynthetic pathway from Anabaena sp. PCC 7120. The ATP-dependent cyclase, along with the homologous AMdnC, introduce up to nine macrocyclizations on three distinct core regions of a precursor peptide, AMdnA. The results presented here provide structural and mechanistic insight into the iterative chemistry of AMdnB. In vitro AMdnB-catalyzed cyclization reactions demonstrate the synthesis of the two predicted tricyclic products from a multi-core precursor peptide substrate, consistent with a distributive mode of catalysis. The X-ray structure of AMdnB shows a structural motif common to ATP-grasp cyclases involved in RiPPs biosynthesis. Additionally, comparison with the noniterative MdnB allows insight into the structural basis for the iterative chemistry. Overall, the presented results provide insight into the general mechanism of iterative enzymes in ribosomally synthesized and post-translationally modified peptide biosynthetic pathways. PubMed: 34664307DOI: 10.1002/prot.26264 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.493 Å) |
Structure validation
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