MRNA (guanine-N7-)-methyltransferase

In enzymology, a mRNA (guanine-N7-)-methyltransferase also known as mRNA cap guanine-N7 methyltransferase is an enzyme that catalyzes the chemical reaction


 * S-adenosyl- L -methionine + G(5')pppR-RNA $$\rightleftharpoons$$ S-adenosyl- L -homocysteine + m7G(5')pppR-RNA (mRNA containing an N7-methylguanine cap)

Thus, the two substrates of this enzyme are S-adenosyl methionine and G(5')pppR-RNA, whereas its two products are S-adenosylhomocysteine and m7G(5')pppR-RNA. This enzyme belongs to the family of transferases, specifically those transferring one-carbon group methyltransferases.

In humans, mRNA cap guanine-N7 methyltransferase is encoded by the RNMT gene.

Nomenclature
The systematic name of this enzyme class is S-adenosyl-L-methionine:mRNA (guanine-N7-)-methyltransferase. Other names in common use include:
 * messenger ribonucleate guanine 7-methyltransferase,
 * guanine-7-methyltransferase,
 * messenger RNA guanine 7-methyltransferase, and
 * S-adenosyl-L-methionine:mRNA (guanine-7-N-)-methyltransferase.
 * cap MTase