D
IPR012854

Copper amine oxidase-like, N-terminal

InterPro entry
Short nameCu_amine_oxidase-like_N
Overlapping
homologous
superfamilies
 

Description

Amine oxidases (AO) are enzymes that catalyse the oxidation of a wide range of biogenic amines including many neurotransmitters, histamine and xenobiotic amines. There are two classes of amine oxidases: flavin-containing (
1.4.3.4
) and copper-containing (
1.4.3.6
). Copper-containing AO act as a disulphide-linked homodimer. They catalyse the oxidation of primary amines to aldehydes, with the subsequent release of ammonia and hydrogen peroxide, which requires one copper ion per subunit and topaquinone as cofactor
[1]
: RCH2NH2 + H2O + O2 = RCHO + NH3 + H2O2

Copper-containing amine oxidases are found in bacteria, fungi, plants and animals. In prokaryotes, the enzyme enables various amine substrates to be used as sources of carbon and nitrogen
[3, 4]
. In eukaryotes they have a broader range of functions, including cell differentiation and growth, wound healing, detoxification and cell signalling
[5]
.

The copper amine oxidases occur as mushroom-shaped homodimers of 70-95kDa, each monomer containing a copper ion and a covalently bound redox cofactor, topaquinone (TPQ). TPQ is formed by post-translational modification of a conserved tyrosine residue. The copper ion is coordinated with three histidine residues and two water molecules in a distorted square pyramidal geometry, and has a dual function in catalysis and TPQ biogenesis. The catalytic domain is the largest of the 3-4 domains found in copper amine oxidases, and consists of a β sandwich of 18 strands in two sheets. The active site is buried and requires a conformational change to allow the substrate access. The two N-terminal domains share a common structural fold, its core consisting of a five-stranded antiparallel β-sheet twisted around an α-helix. The D1 domains from the two subunits comprise the stalk, of the mushroom-shaped dimer, and interact with each other but do not pack tightly against each other
[1, 2]
.

This entry represents a domain found at the N-terminal of certain copper amine oxidases, as well as in related proteins such as cell wall hydrolase and N-acetylmuramoyl-L-alanine amidase. This domain consists of a five-stranded antiparallel β-sheet twisted around an α helix
[1, 2]
.

References

1.Crystal structure of a quinoenzyme: copper amine oxidase of Escherichia coli at 2 A resolution. Parsons MR, Convery MA, Wilmot CM, Yadav KD, Blakeley V, Corner AS, Phillips SE, McPherson MJ, Knowles PF. Structure 3, 1171-84, (1995). View articlePMID: 8591028

2.Visualization of dioxygen bound to copper during enzyme catalysis. Wilmot CM, Hajdu J, McPherson MJ, Knowles PF, Phillips SE. Science 286, 1724-8, (1999). View articlePMID: 10576737

3.Catalytic mechanism of the quinoenzyme amine oxidase from Escherichia coli: exploring the reductive half-reaction. Wilmot CM, Murray JM, Alton G, Parsons MR, Convery MA, Blakeley V, Corner AS, Palcic MM, Knowles PF, McPherson MJ, Phillips SE. Biochemistry 36, 1608-20, (1997). View articlePMID: 9048544

4.Crystal structures of the copper-containing amine oxidase from Arthrobacter globiformis in the holo and apo forms: implications for the biogenesis of topaquinone. Wilce MC, Dooley DM, Freeman HC, Guss JM, Matsunami H, McIntire WS, Ruggiero CE, Tanizawa K, Yamaguchi H. Biochemistry 36, 16116-33, (1997). View articlePMID: 9405045

5.Crystal structure of a eukaryotic (pea seedling) copper-containing amine oxidase at 2.2 A resolution. Kumar V, Dooley DM, Freeman HC, Guss JM, Harvey I, McGuirl MA, Wilce MC, Zubak VM. Structure 4, 943-55, (1996). View articlePMID: 8805580

Cross References

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