OCA at 15:25, 18 October 2023

OCA — Wed, 18 Oct 2023 15:25:10 GMT

←Older revision		Revision as of 15:25, 18 October 2023
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	==NicA2 variant N462Y/W427Y in complex with (S)-nicotine==		==NicA2 variant N462Y/W427Y in complex with (S)-nicotine==
-	<StructureSection load='7khn' size='340' side='right'caption='[[7khn]]' scene=''>	+	<StructureSection load='7khn' size='340' side='right'caption='[[7khn]], [[Resolution\|resolution]] 2.31Å' scene=''>
	== Structural highlights ==		== Structural highlights ==
-	<table><tr><td colspan='2'>Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7KHN OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7KHN FirstGlance]. <br>	+	<table><tr><td colspan='2'>[[7khn]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Pseudomonas_putida_S16 Pseudomonas putida S16]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7KHN OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7KHN FirstGlance]. <br>
-	</td></tr><tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=7khn FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7khn OCA], [https://pdbe.org/7khn PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7khn RCSB], [https://www.ebi.ac.uk/pdbsum/7khn PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7khn ProSAT]</span></td></tr>	+	</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models\|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution\|Resolution]] 2.31Å</td></tr>
		+	<tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=FAD:FLAVIN-ADENINE+DINUCLEOTIDE'>FAD</scene>, <scene name='pdbligand=NCT:(S)-3-(1-METHYLPYRROLIDIN-2-YL)PYRIDINE'>NCT</scene></td></tr>
		+	<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=7khn FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7khn OCA], [https://pdbe.org/7khn PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7khn RCSB], [https://www.ebi.ac.uk/pdbsum/7khn PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7khn ProSAT]</span></td></tr>
	</table>		</table>
		+	== Function ==
		+	[https://www.uniprot.org/uniprot/F8G0P2_PSEP6 F8G0P2_PSEP6]
		+	<div style="background-color:#fffaf0;">
		+	== Publication Abstract from PubMed ==
		+	In Pseudomonas putida, the flavoprotein nicotine oxidoreductase (NicA2) catalyzes the oxidation of (S)-nicotine to N-methyl-myosmine, which is nonenzymatically hydrolyzed to pseudooxynicotine. Structural analysis reveals a monoamine oxidase (MAO)-like fold with a conserved FAD-binding domain and variable substrate-binding domain. The flavoenzyme has a unique variation of the classic aromatic cage with flanking residue pair W427/N462. Previous mechanistic studies using O2 as the oxidizing substrate show that NicA2 has a low apparent Km of 114 nM for (S)-nicotine with a very low apparent turnover number (kcat of 0.006 s(-1)). Herein, the mechanism of NicA2 was analyzed by transient kinetics. Single-site variants of W427 and N462 were used to probe the roles of these residues. Although several variants had moderately higher oxidase activity (7-12-fold), their reductive half-reactions using (S)-nicotine were generally significantly slower than that of wild-type NicA2. Notably, the reductive half-reaction of wild-type NicA2 is 5 orders of magnitude faster than the oxidative half-reaction with an apparent pseudo-first-order rate constant for the reaction of oxygen similar to kcat. X-ray crystal structures of the N462V and N462Y/W427Y variants complexed with (S)-nicotine (at 2.7 and 2.3 A resolution, respectively) revealed no significant active-site rearrangements. A second substrate-binding site was identified in N462Y/W427Y, consistent with observed substrate inhibition. Together, these findings elucidate the mechanism of a flavoenzyme that preferentially oxidizes tertiary amines with an efficient reductive half-reaction and a very slow oxidative half-reaction when O2 is the oxidizing substrate, suggesting that the true oxidizing agent is unknown.
		+
		+	Fast Kinetics Reveals Rate-Limiting Oxidation and the Role of the Aromatic Cage in the Mechanism of the Nicotine-Degrading Enzyme NicA2.,Tararina MA, Dam KK, Dhingra M, Janda KD, Palfey BA, Allen KN Biochemistry. 2021 Feb 2;60(4):259-273. doi: 10.1021/acs.biochem.0c00855. Epub, 2021 Jan 19. PMID:33464876<ref>PMID:33464876</ref>
		+
		+	From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
		+	</div>
		+	<div class="pdbe-citations 7khn" style="background-color:#fffaf0;"></div>
		+	== References ==
		+	<references/>
	__TOC__		__TOC__
	</StructureSection>		</StructureSection>
	[[Category: Large Structures]]		[[Category: Large Structures]]
		+	[[Category: Pseudomonas putida S16]]
	[[Category: Allen KN]]		[[Category: Allen KN]]
	[[Category: Tararina MA]]		[[Category: Tararina MA]]

OCA at 11:12, 3 February 2021

OCA — Wed, 03 Feb 2021 11:12:05 GMT

←Older revision		Revision as of 11:12, 3 February 2021
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-	'''Unreleased structure'''

-	~~The entry~~ 7khn ~~is ON HOLD~~	+	==NicA2 variant N462Y/W427Y in complex with (S)-nicotine==
-		+	<StructureSection load='7khn' size='340' side='right'caption='[[7khn]]' scene=''>
-	~~Authors~~:	+	== Structural highlights ==
-		+	<table><tr><td colspan='2'>Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7KHN OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7KHN FirstGlance]. <br>
-	~~Description~~:	+	</td></tr><tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=7khn FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7khn OCA], [https://pdbe.org/7khn PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7khn RCSB], [https://www.ebi.ac.uk/pdbsum/7khn PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7khn ProSAT]</span></td></tr>
-	[[Category: ~~Unreleased~~ Structures]]	+	</table>
		+	__TOC__
		+	</StructureSection>
		+	[[Category: Large Structures]]
		+	[[Category: Allen KN]]
		+	[[Category: Tararina MA]]

OCA at 06:50, 20 January 2021

OCA — Wed, 20 Jan 2021 06:50:48 GMT

←Older revision		Revision as of 06:50, 20 January 2021
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	'''Unreleased structure'''		'''Unreleased structure'''

-	The entry 7khn is ON HOLD ~~until Paper Publication~~	+	The entry 7khn is ON HOLD

	Authors:		Authors:

OCA at 05:30, 25 November 2020

OCA — Wed, 25 Nov 2020 05:30:30 GMT

←Older revision		Revision as of 05:30, 25 November 2020
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	'''Unreleased structure'''		'''Unreleased structure'''

-	The entry 7khn is ON HOLD	+	The entry 7khn is ON HOLD until Paper Publication

	Authors:		Authors:

OCA: Protected "7khn" [edit=sysop:move=sysop]

OCA — Wed, 28 Oct 2020 19:12:37 GMT

Protected "7khn" [edit=sysop:move=sysop]

←Older revision

Revision as of 19:12, 28 October 2020

OCA: New page: '''Unreleased structure''' The entry 7khn is ON HOLD Authors: Description: Category: Unreleased Structures

OCA — Wed, 28 Oct 2020 19:12:36 GMT

New page: '''Unreleased structure''' The entry 7khn is ON HOLD Authors: Description: Category: Unreleased Structures

New page