8UIQ

H47Q NicC with 2-mercaptopyridine ligand

Summary for 8UIQ

• Entry DOI: 10.2210/pdb8uiq/pdb
• Descriptor: 6-hydroxynicotinate 3-monooxygenase, FLAVIN-ADENINE DINUCLEOTIDE, 2-PYRIDINETHIOL, ... (4 entities in total)
• Functional Keywords: ligand bound, oxidoreductase
• Biological source: Pseudomonas putida KT2440
• Total number of polymer chains: 1
• Total formula weight: 46316.78

Authors

Hicks, K.A.,Perry, K.,Turlington, Z.R.,Vaz Ferreira de Macedo, S. (deposition date: 2023-10-10, release date: 2024-02-21)

Primary citation

Turlington, Z.R.,Vaz Ferreira de Macedo, S.,Perry, K.,Belsky, S.L.,Faust, J.A.,Snider, M.J.,Hicks, K.A.
Ligand bound structure of a 6-hydroxynicotinic acid 3-monooxygenase provides mechanistic insights.
Arch.Biochem.Biophys., 752:109859-109859, 2024

PubMed 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 NicC•2-MP complex in our crystal structure. This complex reveals interesting mechanistic details about the reaction catalyzed by 6-hydroxynicotinic acid 3-monooxygenase.

PubMed: 38104959
DOI: 10.1016/j.abb.2023.109859

Experimental method

X-RAY DIFFRACTION (2.17 Å)