GO:0046406

magnesium protoporphyrin IX methyltransferase activity

GO Category: 
molecular_function
Details: 
Catalysis of the reaction: S-adenosyl-L-methionine(1+) + magnesium protoporphyrin IX = S-adenosyl-L-homocysteine + H(+) + magnesium protoporphyrin IX 13-monomethyl ester.