Precorrin 6Y C5,15 methyltransferase (decarboxylating)

In enzymology, a precorrin-6Y C5,15-methyltransferase (decarboxylating) (EC 2.1.1.132) is an enzyme that catalyzes the chemical reaction

2 S-adenosyl-L-methionine + precorrin-6Y ⇌ 2 S-adenosyl-L-homocysteine + precorrin-8X + CO₂

Thus, the two substrates of this enzyme are S-adenosyl methionine and precorrin 6Y, whereas its 3 products are S-adenosylhomocysteine, precorrin 8X, and CO₂.

This enzyme belongs to the family of transferases, specifically those transferring one-carbon group methyltransferases. The systematic name of this enzyme class is S-adenosyl-L-methionine:1-precorrin-6Y C5,15-methyltransferase (C-12-decarboxylating). Other names in common use include precorrin-6 methyltransferase, and precorrin-6Y methylase. This enzyme participates in porphyrin and chlorophyll metabolism.