xanthosine + S-adenosyl-L-methionine <=> 7-methylxanthosine + S-adenosyl-L-homocysteine
xanthosine + s-adenosyl-l-methionine <=> 7-methylxanthosine + s-adenosyl-l-homocysteine
xanthosine + S-adenosyl-L-methionine <=> 7-methylxanthosine + S-adenosyl-L-homocysteine
xanthosine + s-adenosyl-l-methionine <=> 7-methylxanthosine + s-adenosyl-l-homocysteine