CATH Classification

Domain Context

CATH Clusters

Superfamily Methyltransferase, alpha-helical capping domain
Functional Family

Enzyme Information

2.1.1.158
7-methylxanthosine synthase.
based on mapping to UniProt A4GE69
S-adenosyl-L-methionine + xanthosine = S-adenosyl-L-homocysteine + 7-methylxanthosine.
-!- The enzyme is specific for xanthosine, as XMP and xanthine cannot act as substrates. -!- The enzyme does not have N(1)- or N(3)- methylation activity. -!- This is the first methylation step in the production of caffeine.

UniProtKB Entries (1)

A4GE69
XMT1_COFCA
Coffea canephora
7-methylxanthosine synthase 1

PDB Structure

PDB 2EG5
External Links
Method X-RAY DIFFRACTION
Organism Escherichia
Primary Citation
The structure of two N-methyltransferases from the caffeine biosynthetic pathway
McCarthy, A.A., McCarthy, J.G.
Plant Physiol.
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