Cloning and bacterial expression of protein L -Isoaspartyl methyltransferase 1 (PIMT1) from arabidospsis thaliana
Student name: Ms Tanu Sri
Guide: Dr. Ramakrishnan Sitaraman
Year of completion: 2011
Host Organisation: National Institute of Plant Genome Research
Supervisor (Host Organisation): Dr Manoj Majee
Abstract: The Protein L-isoaspartyl methyltransferase (PIMT) has been proved as an
important repair enzyme in many members of the plant kingdom, and several
organisms in the animal kingdom, during stress-induced damage of proteins.
Under several types of stress conditions, the L-asparginyl and L-aspartyl
residues in proteins tend to spontaneously convert into L-isoaspartyl
residues, which can easily racemize to D-aspartyl residue, leading to loss of
structure and functionality of the protein. This repair enzyme transfers a
methyl group from a donor to the L-isoaspartyl residue to convert it back to
the original amino acid residue, thus preventing the damage of protein. This
enzyme has been reported and studied in several plants, including the model
plant Arabidopsis thaliana (AtPIMT1). Also, another copy of the gene
encoding PIMT (AtPIMT2) has been found at another chromosome in the
same genome, along with its splice variants. This study aims to clone and
express the AtPIMT1 in a suitable bacterial expression system, so that it may
be later characterized functionally.
Keywords: PIMT, AtPIMT1, L-isoaspartyl, protein repair enzyme, stressinduced
damage
