5ttk

From Proteopedia

Crystal Structure of Selenomethionine-incorporated Nicotine Oxidoreductase from Pseudomonas putida

Structural highlights

5ttk is a 4 chain structure with sequence from Pseudomonas putida S16. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 2.51Å
Ligands:	,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

NICA2_PSEP6 Involved in nicotine degradation (PubMed:24204321, PubMed:26237398, PubMed:29812904, PubMed:33432238). Catalyzes the conversion of nicotine to N-methylmyosmine (PubMed:24204321, PubMed:29812904, PubMed:33432238, PubMed:33464876). N-methylmyosmine undergoes spontaneous hydrolysis to form pseudooxynicotine (PN) (PubMed:24204321). S-nicotine is the optimal substrate (PubMed:29812904). Has lower activity with some nicotine analogs, but shows no activity towards neurotransmitters, including serotonin, dopamine, and norepinephrine, nicotine metabolites and common neuroactive drugs (PubMed:29812904). The enzyme is stereospecific with poor activity with (R)-nicotine as the substrate (PubMed:29812904). The c-type cytochrome protein CycN is the physiological electron acceptor (PubMed:33432238). O(2) is a poor electron acceptor (PubMed:33432238, PubMed:33464876).^[1] ^[2] ^[3] ^[4] ^[5]

Publication Abstract from PubMed

The first structure of nicotine oxidoreductase (NicA2) was determined by X-ray crystallography. Pseudomonas putida has evolved nicotine-degrading activity to provide a source of carbon and nitrogen. The structure establishes NicA2 as a member of the monoamine oxidase family. Residues 1-50 are disordered and may play a role in localization. The nicotine-binding site proximal to the isoalloxazine ring of flavin shows an unusual composition of the classical aromatic cage (W427 and N462). The active site architecture is consistent with the proposed binding of the deprotonated form of the substrate and the flavin-dependent oxidation of the pyrrolidone C-N bond followed by nonenzymatic hydrolysis.

Structural Analysis Provides Mechanistic Insight into Nicotine Oxidoreductase from Pseudomonas putida.,Tararina MA, Janda KD, Allen KN Biochemistry. 2016 Dec 6;55(48):6595-6598. Epub 2016 Nov 18. PMID:27933790^[6]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Tang H, Wang L, Wang W, Yu H, Zhang K, Yao Y, Xu P. Systematic unraveling of the unsolved pathway of nicotine degradation in Pseudomonas. PLoS Genet. 2013 Oct;9(10):e1003923. PMID:24204321 doi:10.1371/journal.pgen.1003923
↑ Xue S, Schlosburg JE, Janda KD. A New Strategy for Smoking Cessation: Characterization of a Bacterial Enzyme for the Degradation of Nicotine. J Am Chem Soc. 2015 Aug 19;137(32):10136-9. PMID:26237398 doi:10.1021/jacs.5b06605
↑ Tararina MA, Xue S, Smith LC, Muellers SN, Miranda PO, Janda KD, Allen KN. Crystallography Coupled with Kinetic Analysis Provides Mechanistic Underpinnings of a Nicotine-Degrading Enzyme. Biochemistry. 2018 Jul 3;57(26):3741-3751. doi: 10.1021/acs.biochem.8b00384. Epub, 2018 Jun 13. PMID:29812904 doi:http://dx.doi.org/10.1021/acs.biochem.8b00384
↑ Dulchavsky M, Clark CT, Bardwell JCA, Stull F. A cytochrome c is the natural electron acceptor for nicotine oxidoreductase. Nat Chem Biol. 2021 Mar;17(3):344-350. PMID:33432238 doi:10.1038/s41589-020-00712-3
↑ Tararina MA, Dam KK, Dhingra M, Janda KD, Palfey BA, Allen KN. Fast Kinetics Reveals Rate-Limiting Oxidation and the Role of the Aromatic Cage in the Mechanism of the Nicotine-Degrading Enzyme NicA2. Biochemistry. 2021 Feb 2;60(4):259-273. PMID:33464876 doi:10.1021/acs.biochem.0c00855
↑ Tararina MA, Janda KD, Allen KN. Structural Analysis Provides Mechanistic Insight into Nicotine Oxidoreductase from Pseudomonas putida. Biochemistry. 2016 Dec 6;55(48):6595-6598. Epub 2016 Nov 18. PMID:27933790 doi:http://dx.doi.org/10.1021/acs.biochem.6b00963