Arabidopsis Protein Repair L-Isoaspartyl Methyltransferases: Predominant Activities at Lethal Temperatures.

Protein L-isoaspartyl (D-aspartyl) O-methyltransferases (EC 2.1.1.

A second protein L-isoaspartyl methyltransferase gene in Arabidopsis produces two transcripts whose products are sequestered in the nucleus.

The spontaneous and deleterious conversion of l-asparaginyl and l-aspartyl protein residues to l-iso-Asp or d-Asp occurs as proteins age and is accelerated under stressful conditions. Arabidopsis (Arabidopsis L. Heynh.