PCMT1 transfers CH3 from AdoMet to isoAsp to form MetAsp

Stable Identifier
Reaction [transition]
Homo sapiens
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Protein-L-isoaspartate (D-aspartate) O-methyltransferase (PCMT1, PIMT EC transfers the methyl group from S-adenosyl-L-methionine (AdoMet) to the alpha side-chain carboxyl group of L-isoaspartyl and D-aspartatyl amino acids (Murray & Clarke 1986, Johnson et al. 1987, Galletti et al. 1988, Lowenson & Clarke 1992, The resulting methyl ester (MetAsp) undergoes spontaneous transformation to L-succinimide, which spontaneously hydrolyses to generates L-aspartyl residues or L-isoaspartyl residues. This repair process helps to maintain overall protein integrity. When PCMT1 is not present in cells, the abnormal aspartyl residues accumulate. Pcmt1 knockout mice exhibit fatal progressive epilepsy (Yamamoto et al. 1998).

Literature References
PubMed ID Title Journal Year
7592526 Characterization of three cDNAs encoding two isozymes of an isoaspartyl protein carboxyl methyltransferase from human erythroid leukemia cells

Takeda, R, Sato, M, Takahara, J, Mizobuchi, M, Murao, K

J. Biochem. 1995
3624258 Partial repair of deamidation-damaged calmodulin by protein carboxyl methyltransferase

Langmack, EL, Johnson, BA, Aswad, DW

J. Biol. Chem. 1987
Catalyst Activity

protein-L-isoaspartate (D-aspartate) O-methyltransferase activity of PCMT1 [cytosol]

Orthologous Events
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