Expression Vector Comprising a Polynucleotide Encoding a Modified Glutamine Synthetase and a Method for Preparing a Target Protein Employing the Same

Abstract

The present invention relates to a vector comprising a polynucleotide encoding a modified glutamine synthetase (GS), and a method for preparing a target protein employing the same. More particulary, the present invention relates to a modified GS having an increased sensitivity to a glutamine synthetase (GS) inhibitor, a polynucleotide encoding the modified GS, a vector comprising the polynucleotide, a transformat comprising the vector, and a method for preparing a target protein using the transformat.

1 . A modified glutamine synthetase (GS), wherein glycine (Gly, G) at position 299 of a glutamine synthetase having an amino acid sequence shown in SEQ ID NO. 4 is substituted with arginine (Arg, R). 
     
     
         2 . The modified glutamine synthetase according to  claim 1 , having an increased sensitivity to a glutamine synthetase inhibitor, compared to the glutamine synthetase having an amino acid sequence shown in SEQ ID NO.4. 
     
     
         3 . The modified glutamine synthetase according to  claim 2 , wherein the glutamine synthetase inhibitor is selected from the group consisting of glycine, alanine, tryptophan, histidine, glucosamine-6-phosphate, cytidine triphosphate, methionine sulphoximine (MSX), and combinations thereof. 
     
     
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         16 . A target protein prepared by a method comprising culturing a transformant comprising a vector for expression of a target protein, comprising the polynucleotide encoding a modified glutamine synthetase wherein glycine (Gly, G) at position 299 of a glutamine synthetase having an amino acid sequence shown in SEQ ID NO. 4 is substituted with arginine (Arg, R).