| Structural highlights
Function
[AAUA_ALCFA] Oxidizes primary aromatic amines and, more slowly, some long-chain aliphatic amines, but not methylamine or ethylamine. Uses azurin as an electron acceptor to transfer electrons from the reduced tryptophylquinone cofactor.[1] [2] [3] [4] [5] [6] [7] [AAUB_ALCFA] Oxidizes primary aromatic amines and, more slowly, some long-chain aliphatic amines, but not methylamine or ethylamine. Uses azurin as an electron acceptor to transfer electrons from the reduced tryptophylquinone cofactor.[8] [9] [10] [11]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
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.
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[12]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Chistoserdov AY. Cloning, sequencing and mutagenesis of the genes for aromatic amine dehydrogenase from Alcaligenes faecalis and evolution of amine dehydrogenases. Microbiology. 2001 Aug;147(Pt 8):2195-202. PMID:11495996
- ↑ Hothi P, Khadra KA, Combe JP, Leys D, Scrutton NS. Tryptophan tryptophylquinone cofactor biogenesis in the aromatic amine dehydrogenase of Alcaligenes faecalis. Cofactor assembly and catalytic properties of recombinant enzyme expressed in Paracoccus denitrificans. FEBS J. 2005 Nov;272(22):5894-909. PMID:16279953 doi:http://dx.doi.org/EJB4990
- ↑ Govindaraj S, Eisenstein E, Jones LH, Sanders-Loehr J, Chistoserdov AY, Davidson VL, Edwards SL. Aromatic amine dehydrogenase, a second tryptophan tryptophylquinone enzyme. J Bacteriol. 1994 May;176(10):2922-9. PMID:8188594
- ↑ Edwards SL, Davidson VL, Hyun YL, Wingfield PT. Spectroscopic evidence for a common electron transfer pathway for two tryptophan tryptophylquinone enzymes. J Biol Chem. 1995 Mar 3;270(9):4293-8. PMID:7876189
- ↑ Sukumar N, Chen ZW, Ferrari D, Merli A, Rossi GL, Bellamy HD, Chistoserdov A, Davidson VL, Mathews FS. Crystal structure of an electron transfer complex between aromatic amine dehydrogenase and azurin from Alcaligenes faecalis. Biochemistry. 2006 Nov 14;45(45):13500-10. PMID:17087503 doi:http://dx.doi.org/10.1021/bi0612972
- ↑ Roujeinikova A, Scrutton NS, Leys D. Atomic level insight into the oxidative half-reaction of aromatic amine dehydrogenase. J Biol Chem. 2006 Dec 29;281(52):40264-72. Epub 2006 Sep 27. PMID:17005560 doi:http://dx.doi.org/10.1074/jbc.M605559200
- ↑ Masgrau L, Roujeinikova A, Johannissen LO, Hothi P, Basran J, Ranaghan KE, Mulholland AJ, Sutcliffe MJ, Scrutton NS, Leys D. Atomic description of an enzyme reaction dominated by proton tunneling. Science. 2006 Apr 14;312(5771):237-41. PMID:16614214 doi:312/5771/237
- ↑ Chistoserdov AY. Cloning, sequencing and mutagenesis of the genes for aromatic amine dehydrogenase from Alcaligenes faecalis and evolution of amine dehydrogenases. Microbiology. 2001 Aug;147(Pt 8):2195-202. PMID:11495996
- ↑ Hothi P, Khadra KA, Combe JP, Leys D, Scrutton NS. Tryptophan tryptophylquinone cofactor biogenesis in the aromatic amine dehydrogenase of Alcaligenes faecalis. Cofactor assembly and catalytic properties of recombinant enzyme expressed in Paracoccus denitrificans. FEBS J. 2005 Nov;272(22):5894-909. PMID:16279953 doi:http://dx.doi.org/EJB4990
- ↑ Govindaraj S, Eisenstein E, Jones LH, Sanders-Loehr J, Chistoserdov AY, Davidson VL, Edwards SL. Aromatic amine dehydrogenase, a second tryptophan tryptophylquinone enzyme. J Bacteriol. 1994 May;176(10):2922-9. PMID:8188594
- ↑ Masgrau L, Roujeinikova A, Johannissen LO, Hothi P, Basran J, Ranaghan KE, Mulholland AJ, Sutcliffe MJ, Scrutton NS, Leys D. Atomic description of an enzyme reaction dominated by proton tunneling. Science. 2006 Apr 14;312(5771):237-41. PMID:16614214 doi:312/5771/237
- ↑ Roujeinikova A, Hothi P, Masgrau L, Sutcliffe MJ, Scrutton NS, Leys D. New insights into the reductive half-reaction mechanism of aromatic amine dehydrogenase revealed by reaction with carbinolamine substrates. J Biol Chem. 2007 Aug 17;282(33):23766-77. Epub 2007 May 1. PMID:17475620 doi:10.1074/jbc.M700677200
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