DNA ENCODING BACTERIAL ASPARTATE KINASE-III AND METHOD FOR PREPARING L-LYSINE Russian patent published in 2003 - IPC

FIELD: molecular biology, biochemistry, biotechnology, amino acids. SUBSTANCE: invention relates to method for preparing L-lysine by fermentation and also to DNA used in this method. The represented DNA encodes aspartate kinase-III in microorganisms belonging to genus Escherichia and used for preparing L-amino acids. This DNA comprises mutation in encoding site that provides removal of inhibitory effect of lysine of activity of indicated aspartate kinase-III by feedback inhibition mechanism. Method for preparing L-lysine involves preparing indicated DNA and its incorporation into cells for preparing microorganism-transformants of genus Escherichia. Then incubation of these microorganisms is carried out in corresponding cultural medium that results to production and accumulation of L-lysine in this culture followed by L-lysine isolation from its. Inventions provide preparing aspartate kinase-III from microorganisms of genus Escherichia where inhibition by L-lysine by feedback inhibition mechanism is removed effectively. EFFECT: improved method of L-lysine preparing. 3 cl, 7 tbl, 3 dwg, 5 ex