Guanidinoacetate N-methyltransferase

Guanidinoacetate N-methyltransferase is an is_associated_with::enzyme that catalyzes the is_associated_with::chemical reaction and is encoded by gene GAMT located on chromosome 19p13.3.


 * S-adenosyl-L-methionine + guanidinoacetate $$\rightleftharpoons$$ S-adenosyl-L-homocysteine + creatine

Thus, the two substrates of this enzyme are S-adenosyl methionine and is_associated_with::guanidinoacetate, whereas its two products are is_associated_with::S-adenosylhomocysteine and is_associated_with::creatine.

This enzyme belongs to the family of is_associated_with::transferases, specifically those transferring one-carbon group methyltransferases. The systematic name of this enzyme class is S-adenosyl-L-methionine:N-guanidinoacetate methyltransferase. Other names in common use include GA methylpherase, guanidinoacetate methyltransferase, guanidinoacetate transmethylase, methionine-guanidinoacetic transmethylase, and guanidoacetate methyltransferase. This enzyme participates in is_associated_with::glycine, serine and threonine metabolism and is_associated_with::arginine and proline metabolism.

The protein encoded by this gene is a methyltransferase that converts is_associated_with::guanidoacetate to is_associated_with::creatine, using S-adenosylmethionine as the methyl donor. Defects in this gene have been implicated in neurologic syndromes and muscular hypotonia, probably due to creatine deficiency and accumulation of guanidinoacetate in the brain of affected individuals. Two transcript variants encoding different isoforms have been described for this gene.

Structural studies
As of late 2007, 7 structures have been solved for this class of enzymes, with PDB accession codes, , , , , , and.