9T62
Crystal structure of ortho-aminophenol oxidase SmNspF from Streptomyces murayamaensis
Summary for 9T62
| Entry DOI | 10.2210/pdb9t62/pdb |
| Descriptor | O-aminophenol oxidase, COPPER (II) ION, CHLORIDE ION, ... (4 entities in total) |
| Functional Keywords | type-iii copper enzyme, polyphenol oxidase, nitroso-forming activity, c-nitrosation, oxidoreductase |
| Biological source | Streptomyces murayamaensis |
| Total number of polymer chains | 2 |
| Total formula weight | 72099.68 |
| Authors | Le Xuan, H.,Rompel, A. (deposition date: 2025-11-06, release date: 2026-02-11, Last modification date: 2026-05-13) |
| Primary citation | Le Xuan, H.,Rompel, A. Structural insights into ortho -aminophenol oxidases: kinetic and crystallographic characterization of Sm NspF and Sg GriF. Inorg Chem Front, 13:3786-3794, 2026 Cited by PubMed Abstract: Actinobacteria-derived -aminophenol oxidases (AOs) represent a largely unexplored subclass of type-III copper enzymes with catalytic properties distinct from tyrosinases and catechol oxidases. The determination of the first crystal structure of an AO (NspF) displays unique loop insertions and important second-sphere amino acids in vicinity of the binuclear copper center. The substrate-guiding effect of the second activity controller (His) influences the binding affinity for carboxyl-containing substrates in the AOs NspF and GriF. Thus, kinetic investigations reveal both overlapping and distinct substrate preferences for NspF and GriF: while both enzymes oxidize monophenols, -aminophenols, and -diphenols, they do so at significantly different reaction rates. NspF preferentially oxidizes carboxylated substrates such as 3,4-dihydroxybenzoic acid and 3-amino-4-hydroxybenzoic acid, whereas GriF exhibits higher activity toward -methylated analogs, including 4-methylcatechol and 2-amino-4-methylphenol. Remarkably, both enzymes display enzymatic activities beyond the known AO reactivity spectrum by oxidizing 2-aminoresorcinol and -phenylenediamine, which underlies the high versatility of the binuclear copper center. Altogether, these findings provide a structural basis for AO's enzymatic activity and broaden the known catalytic spectrum, which enables the prediction of catalytic properties in type-III copper proteins based on their amino acid sequence. PubMed: 41836335DOI: 10.1039/d5qi02495a PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.4 Å) |
Structure validation
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