Ligand bound structure of a 6-hydroxynicotinic acid 3-monooxygenase provides mechanistic insights.
Arch Biochem Biophys
; 752: 109859, 2024 02.
Article
en En
| MEDLINE
| ID: mdl-38104959
ABSTRACT
6-Hydroxynicotinic acid 3-monooxygenase (NicC) is a bacterial enzyme involved in the degradation of nicotinic acid. This enzyme is a Class A flavin-dependent monooxygenase that catalyzes a unique decarboxylative hydroxylation. The unliganded structure of this enzyme has previously been reported and studied using steady- and transient-state kinetics to support a comprehensive kinetic mechanism. Here we report the crystal structure of the H47Q NicC variant in both a ligand-bound (solved to 2.17 Å resolution) and unliganded (1.51 Å resolution) form. Interestingly, in the liganded form, H47Q NicC is bound to 2-mercaptopyridine (2-MP), a contaminant present in the commercial stock of 6-mercaptopyridine-3-carboxylic acid(6-MNA), a substrate analogue. 2-MP binds weakly to H47Q NicC and is not a substrate for the enzyme. Based on kinetic and thermodynamic characterization, we have fortuitously captured a catalytically inactive H47Q NicCâ¢2-MP complex in our crystal structure. This complex reveals interesting mechanistic details about the reaction catalyzed by 6-hydroxynicotinic acid 3-monooxygenase.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Flavina-Adenina Dinucleótido
/
Oxigenasas de Función Mixta
Idioma:
En
Revista:
Arch Biochem Biophys
Año:
2024
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos