FIELD: biotechnology.
SUBSTANCE: disclosed is a polypeptide involved in the production of a branched-chain amino acid, wherein the amino acid at any one or more corresponding positions 217, 310, 403 and 462 from the N-terminal in the amino acid sequence of SEQ ID NO: 1 is replaced with another amino acid, where the other amino acid is alanine (Ala), where the polypeptide has homology or identity of 90% or more with SEQ ID NO: 1. Also disclosed is a polynucleotide encoding said polypeptide, an expression vector containing said polynucleotide, a microorganism of the genus Corynebacterium, producing a branched-chain amino acid and containing one or more of the following: said polypeptide, polynucleotide and vector. Also disclosed is a method of producing a branched-chain amino acid.
EFFECT: invention enables to obtain a branched chain amino acid with high output and reduced output of by-products.
10 cl, 19 tbl, 6 ex
