2ok6: Difference between revisions
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[[Image:2ok6.gif|left|200px]] | [[Image:2ok6.gif|left|200px]] | ||
'''Crystal structure of aromatic amine dehydrogenase TTQ-formamide adduct oxidized with ferricyanide.''' | {{Structure | ||
|PDB= 2ok6 |SIZE=350|CAPTION= <scene name='initialview01'>2ok6</scene>, resolution 1.45Å | |||
|SITE= <scene name='pdbsite=AC1:Bez+Binding+Site+For+Residue+H+2001'>AC1</scene> and <scene name='pdbsite=AC2:Bez+Binding+Site+For+Residue+D+2002'>AC2</scene> | |||
|LIGAND= <scene name='pdbligand=BEZ:BENZOIC ACID'>BEZ</scene> | |||
|ACTIVITY= [http://en.wikipedia.org/wiki/Aralkylamine_dehydrogenase Aralkylamine dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.4.99.4 1.4.99.4] | |||
|GENE= | |||
}} | |||
'''Crystal structure of aromatic amine dehydrogenase TTQ-formamide adduct oxidized with ferricyanide.''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
2OK6 is a [ | 2OK6 is a [[Protein complex]] structure of sequences from [http://en.wikipedia.org/wiki/Alcaligenes_faecalis Alcaligenes faecalis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2OK6 OCA]. | ||
==Reference== | ==Reference== | ||
New insights into the reductive half-reaction mechanism of aromatic amine dehydrogenase revealed by reaction with carbinolamine substrates., Roujeinikova A, Hothi P, Masgrau L, Sutcliffe MJ, Scrutton NS, Leys D, J Biol Chem. 2007 Aug 17;282(33):23766-77. Epub 2007 May 1. PMID:[http:// | New insights into the reductive half-reaction mechanism of aromatic amine dehydrogenase revealed by reaction with carbinolamine substrates., Roujeinikova A, Hothi P, Masgrau L, Sutcliffe MJ, Scrutton NS, Leys D, J Biol Chem. 2007 Aug 17;282(33):23766-77. Epub 2007 May 1. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/17475620 17475620] | ||
[[Category: Alcaligenes faecalis]] | [[Category: Alcaligenes faecalis]] | ||
[[Category: Aralkylamine dehydrogenase]] | [[Category: Aralkylamine dehydrogenase]] | ||
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[[Category: ttq]] | [[Category: ttq]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 18:00:44 2008'' | ||
Revision as of 19:00, 20 March 2008
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| , resolution 1.45Å | |||||||
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| Sites: | and | ||||||
| Ligands: | |||||||
| Activity: | Aralkylamine dehydrogenase, with EC number 1.4.99.4 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal structure of aromatic amine dehydrogenase TTQ-formamide adduct oxidized with ferricyanide.
OverviewOverview
Aromatic amine dehydrogenase uses a tryptophan tryptophylquinone (TTQ) cofactor to oxidatively deaminate primary aromatic amines. In the reductive half-reaction, a proton is transferred from the substrate C1 to betaAsp-128 O-2, in a reaction that proceeds by H-tunneling. Using solution studies, kinetic crystallography, and computational simulation we show that the mechanism of oxidation of aromatic carbinolamines is similar to amine oxidation, but that carbinolamine oxidation occurs at a substantially reduced rate. This has enabled us to determine for the first time the structure of the intermediate prior to the H-transfer/reduction step. The proton-betaAsp-128 O-2 distance is approximately 3.7A, in contrast to the distance of approximately 2.7A predicted for the intermediate formed with the corresponding primary amine substrate. This difference of approximately 1.0 A is due to an unexpected conformation of the substrate moiety, which is supported by molecular dynamic simulations and reflected in the approximately 10(7)-fold slower TTQ reduction rate with phenylaminoethanol compared with that with primary amines. A water molecule is observed near TTQ C-6 and is likely derived from the collapse of the preceding carbinolamine TTQ-adduct. We suggest this water molecule is involved in consecutive proton transfers following TTQ reduction, and is ultimately repositioned near the TTQ O-7 concomitant with protein rearrangement. For all carbinolamines tested, highly stable amide-TTQ adducts are formed following proton abstraction and TTQ reduction. Slow hydrolysis of the amide occurs after, rather than prior to, TTQ oxidation and leads ultimately to a carboxylic acid product.
About this StructureAbout this Structure
2OK6 is a Protein complex structure of sequences from Alcaligenes faecalis. Full crystallographic information is available from OCA.
ReferenceReference
New insights into the reductive half-reaction mechanism of aromatic amine dehydrogenase revealed by reaction with carbinolamine substrates., Roujeinikova A, Hothi P, Masgrau L, Sutcliffe MJ, Scrutton NS, Leys D, J Biol Chem. 2007 Aug 17;282(33):23766-77. Epub 2007 May 1. PMID:17475620
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