KEGG ENZYME: 1.4.3.27

ENZYME: 1.4.3.27

Entry

EC 1.4.3.27                 Enzyme

Name

homospermidine oxidase;
HSO

Class

Oxidoreductases;
Acting on the CH-NH2 group of donors;
With oxygen as acceptor

Sysname

homospermidine:oxygen oxidase (deaminating, cyclizing)

Reaction(IUBMB)

sym-homospermidine + 2 O2 + H2O = 1-formylpyrrolizidine + 2 H2O2 + 2 NH3 (overall reaction) [RN:R13141];
(1a) sym-homospermidine + O2 = N-(4-aminobutylpyrrolinium) ion + H2O2 + NH3 [RN:R13138];
(1b) N-(4-aminobutylpyrrolinium) ion + O2 + H2O = N-(4-oxobutylpyrrolinium) ion + NH3 + H2O2 [RN:R13139];
(1c) N-(4-oxobutylpyrrolinium) ion = 1-formylpyrrolizidine (spontaneous) [RN:R13140]

Reaction(KEGG)

R13138 R13139 R13140 R13141

Substrate

sym-homospermidine [CPD:C06366];
O2 [CPD:C00007];
H2O [CPD:C00001];
N-(4-aminobutylpyrrolinium) ion [CPD:C22646];
N-(4-oxobutylpyrrolinium) ion [CPD:C22647]

Product

1-formylpyrrolizidine [CPD:C22648];
H2O2 [CPD:C00027];
NH3 [CPD:C00014];
N-(4-aminobutylpyrrolinium) ion [CPD:C22646];
N-(4-oxobutylpyrrolinium) ion [CPD:C22647]

Comment

The copper-containing enzyme has been isolated from the plant Heliotropium indicum. It is involved in the biosynthesis of the pyrrolizidine alkaloid (-)-trachelanthamidine which acts as a secondary metabolite for the defense against herbivores. The oxidation of sym-homospermidine proceeds in three steps and results in a cyclization.

History

EC 1.4.3.27 created 2022

Orthology

K26346

homospermidine oxidase

Genes

SMIL:

130991493 130991497

SHIS:

125192233

RVL:

131310176

AEW:

130757234

Reference

1 [PMID:35212762]

Authors

Zakaria MM, Stegemann T, Sievert C, Kruse LH, Kaltenegger E, Girreser U, Cicek SS, Nimtz M, Ober D.

Title

Insights into polyamine metabolism: homospermidine is double-oxidized in two discrete steps by a single copper-containing amine oxidase in pyrrolizidine alkaloid biosynthesis.

Journal

Plant Cell 34:2364-2382 (2022)
DOI:10.1093/plcell/koac068

Sequence

[ag:UNJ44779]

Other DBs

ExplorEnz - The Enzyme Database:

1.4.3.27

IUBMB Enzyme Nomenclature:

1.4.3.27

ExPASy - ENZYME nomenclature database:

1.4.3.27

BRENDA, the Enzyme Database:

1.4.3.27

LinkDB

DBGET integrated database retrieval system