2.1.1.158	S-adenosyl-L-methionine + xanthosine = S-adenosyl-L-homocysteine + 7-methylxanthosine	-	-	
2.1.1.158	S-adenosyl-L-methionine + xanthosine = S-adenosyl-L-homocysteine + 7-methylxanthosine	a catalytic residue is Gln161, cosubstrate and substrate binding site structures involving the Ser316 for xanthosine recognition, overview	670598	
2.1.1.158	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 [2,4]. The enzyme does not have N1- or N3- methylation activity. This is the first methylation step in the production of caffeine.	-