FIELD: biotechnology.
SUBSTANCE: following is proposed: a mutated polypeptide with isopropyl malate synthase activity containing the amino acid sequence SEQ ID NO: 1 or SEQ ID NO: 16, where the proline at position 247 or 212, respectively, is replaced by cysteine. Also the following is proposed: a mutated polypeptide having isopropyl malate synthase activity containing the amino acid sequence SEQ ID NO: 1, where (1) proline at position 247 is replaced by cysteine and (2) where arginine at position 558 is replaced by histidine and/or where glycine at position 561 is replaced by aspartic acid. Besides, the following is proposed: a polynucleotide encoding the said mutated polypeptide, an expression vector containing the said polynucleotide, a microorganism capable of producing L-leucine, a composition for producing L-leucine and a method of producing L-leucine.
EFFECT: invention makes it possible to obtain L-leucine with high yield.
13 cl, 10 tbl, 4 ex
