8U07
Imine reductase RedE bound with NADP+ and arcyriaflavin A (secondary site)
Summary for 8U07
| Entry DOI | 10.2210/pdb8u07/pdb |
| Descriptor | RedE, 1,2-ETHANEDIOL, Arcyriaflavin A, ... (9 entities in total) |
| Functional Keywords | indolocarbazole, imine reductase, nadph-dependent, biosynthetic protein |
| Biological source | uncultured bacterium |
| Total number of polymer chains | 2 |
| Total formula weight | 68969.89 |
| Authors | Daniel-Ivad, P.,Ryan, K.S. (deposition date: 2023-08-28, release date: 2024-09-04, Last modification date: 2025-03-05) |
| Primary citation | Daniel-Ivad, P.,Ryan, K.S. An imine reductase that captures reactive intermediates in the biosynthesis of the indolocarbazole reductasporine. J.Biol.Chem., 300:105642-105642, 2024 Cited by PubMed Abstract: Imine reductases (IREDs) and reductive aminases have been used in the synthesis of chiral amine products for drug manufacturing; however, little is known about their biological contexts. Here we employ structural studies and site-directed mutagenesis to interrogate the mechanism of the IRED RedE from the biosynthetic pathway to the indolocarbazole natural product reductasporine. Cocrystal structures with the substrate-mimic arcyriaflavin A reveal an extended active site cleft capable of binding two indolocarbazole molecules. Site-directed mutagenesis of a conserved aspartate in the primary binding site reveals a new role for this residue in anchoring the substrate above the NADPH cofactor. Variants targeting the secondary binding site greatly reduce catalytic efficiency, while accumulating oxidized side-products. As indolocarbazole biosynthetic intermediates are susceptible to spontaneous oxidation, we propose the secondary site acts to protect against autooxidation, and the primary site drives catalysis through precise substrate orientation and desolvation effects. The structure of RedE with its extended active site can be the starting point as a new scaffold for engineering IREDs and reductive aminases to intercept large substrates relevant to industrial applications. PubMed: 38199566DOI: 10.1016/j.jbc.2024.105642 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.63 Å) |
Structure validation
Download full validation report
