Glycine Amidinotransferase (GATM)

GATM encodes a mitochondrial enzyme that belongs to the amidinotransferase family. This enzyme is involved in creatine biosynthesis, whereby it catalyzes the transfer of a guanido group from L-arginine to glycine, resulting in guanidinoacetic acid, the immediate precursor of creatine. Mutations in this gene cause arginine:glycine amidinotransferase deficiency, an inborn error of creatine synthesis characterized by mental retardation, language impairment, and behavioral disorders.

The largest human cDNA sequence encodes a 423-amino acid polypeptide including a 37-amino acid signal sequence. The mature porcine and human proteins are 94% identical to each other and 36% identical to bacterial L-arginine:inosamine phosphate amidinotransferase.