Patent ID: 7625734

Claim:
An isolated enzymatically-active protein possessing a glutamine:fructose-6-phosphate amidotransferase (GFAT) activity comprising: a GFAT sequence and at least one purification tag sequence, the purification tag sequence being inserted between two consecutive amino acids of the GFAT sequence corresponding to the sequences: SEQ ID NO: 8, consisting of a sequence SEQ ID NO: 2 in which a hexa-histidine is inserted between amino acids 299 and 300, or SEQ ID NO: 10, consisting of a sequence SEQ ID NO: 4 in which a hexa-histidine is inserted between amino acids 300 and 301, or SEQ ID NO: 12, consisting of a sequence SEQ ID NO: 6 in which a hexa-histidine is inserted between amino acids 317 and 318.