MODIFIED PHOSPHOENOLPYRUVATE CARBOXYLASE, DNA FRAGMENT, STRAIN ESCHERICHIA COLI, RECOMBINANT DNA, METHOD OF PREPARING AMINO ACID (VARIANTS), METHOD OF ESCHERICHIA COLI CELLS SELECTION, METHOD OF PREPARING MODIFIED PHOSPHOENOLPYRUVATE CARBOXYLASE, METHOD OF PREPARING DNA FRAGMENT AND METHOD OF MICROORGANISM PREPARING Russian patent published in 1999 - IPC

FIELD: molecular biology, genetic engineering, biotechnology. SUBSTANCE: invention proposes phosphoenolpyruvate carboxylase where glutamic acid residue at position 625 is substituted with lysine and/or arginine residue at position 222 and/or glutamic acid residue at position 223 is substituted with histidine residue and lysine residue, respectively. Also, serine residue at position 288, glutamic acid residue at position 289, methionine residue at position 551 and glutamic acid residue at position 804 can be substituted with phenylalanine residue, lysine residue, isoleucine residue and lysine residue, respectively. Also, alanine residue at position 867 can be substituted with threonine residue and/or arginine residue at position 438 can be substituted with cysteine residue and/or lysine residue at position 620 can be substituted with serine residue. Phosphoenolpyruvate carboxylase is produced by Escherichia coli strain. Modified phosphoenolpyruvate carboxylase shows low sensitivity to inhibition effect of aspartic acid. EFFECT: improved method of preparing and selection. 18 cl, 13 dwg, 9 tbl, 6 ex