InterPro domain: IPR016651

This group represents the Ppm1 subgroup of leucine carboxymethyltransferases.

Ppm1 regulates the activity of serine/threonine phosphatase 2A (PP2A) through methylation of the C-terminal leucine residue of the catalytic subunit of PP2A [ 1 , 2 , 3 ]. This affects the heteromultimeric composition of PP2A which in turn affects protein recognition and substrate specificity. Like many other methyltransferases Ppm1 uses S-adenosylmethionine (SAM) as the methyl donor. Ppm1 contains the common SAM-dependent methyltransferase core fold, with various insertions and additions creating a specific PP2A binding site [ 4 ].

1. Purification of porcine brain protein phosphatase 2A leucine carboxyl methyltransferase and cloning of the human homologue. Biochemistry 38, 16539-47
2. Protein phosphatase methyltransferase 1 (Ppm1p) is the sole activity responsible for modification of the major forms of protein phosphatase 2A in yeast. Arch. Biochem. Biophys. 395, 239-45
3. Carboxyl methylation of the phosphoprotein phosphatase 2A catalytic subunit promotes its functional association with regulatory subunits in vivo. EMBO J. 19, 5672-81
4. Structure of protein phosphatase methyltransferase 1 (PPM1), a leucine carboxyl methyltransferase involved in the regulation of protein phosphatase 2A activity. J. Biol. Chem. 279, 8351-8