KEGG   ENZYME: 3.2.2.25Help
Entry
EC 3.2.2.25                 Enzyme                                 

Name
N-methyl nucleosidase;
7-methylxanthosine nucleosidase;
N-MeNase;
N-methyl nucleoside hydrolase;
methylpurine nucleosidase
Class
Hydrolases;
Glycosylases;
Hydrolysing N-glycosyl compounds
BRITE hierarchy
Sysname
7-methylxanthosine ribohydrolase
Reaction(IUBMB)
7-methylxanthosine + H2O = 7-methylxanthine + D-ribose [RN:R07918]
Reaction(KEGG)
Substrate
7-methylxanthosine [CPD:C16352];
H2O [CPD:C00001]
Product
7-methylxanthine [CPD:C16353];
D-ribose [CPD:C00121]
Comment
The enzyme preferentially hydrolyses 3- and 7-methylpurine nucleosides, such as 3-methylxanthosine, 3-methyladenosine and 7-methylguanosine. Hydrolysis of 7-methylxanthosine to form 7-methylxanthine is the second step in the caffeine-biosynthesis pathway.
History
EC 3.2.2.25 created 2007
Pathway
ec00232  Caffeine metabolism
ec01100  Metabolic pathways
ec01110  Biosynthesis of secondary metabolites
Reference
1
  Authors
Negishi, O., Ozawa, T. and Imagawa, H.
  Title
N-Methyl nucleosidase from tea leaves.
  Journal
Agric Biol Chem 52:169-175 (1988)
Other DBs
ExplorEnz - The Enzyme Database: 3.2.2.25
IUBMB Enzyme Nomenclature: 3.2.2.25
ExPASy - ENZYME nomenclature database: 3.2.2.25
BRENDA, the Enzyme Database: 3.2.2.25

DBGET integrated database retrieval system