1.1.1.3 G378E feedback resistance of the enzyme 246394 1.1.1.3 G378S construction of a homoserine dehydrogenase mutant HDG378S, encoded by hom1, in Corynebacterium glutamicum strain IWJ001, one of the best L-isoleucine producing strains. Strain HDG378S is partially resistant to L-threonine with the half maximal inhibitory concentration between 12 and 14 mM. Overexpression of lysC1, hom1 and thrB1 increased L-threonine and L-lysine production in Corynebacterium glutamicum ATCC13869 by 96folds and 21.2folds, respectively, overview -, 738802 1.1.1.3 G433R site-directed mutagenesis, strain HS33/pACYC-pycP458S-thrAG433R-lysC shows increased activity (62.4% of the maximum theoretical yield) -, 760402 1.1.1.3 H309A decrease of catalytic activity and elimination of substrate inhibition 246402 1.1.1.3 K105A site-directed double-primer PCR mutagenesis -, 739791 1.1.1.3 K105R site-directed double-primer PCR mutagenesis -, 739791 1.1.1.3 K195A site-directed mutagenesis, inactive mutant. In the crystal structure, the positions of Lys195 and L-Hse are significantly retained with those of the wild-type enzyme, enzyme crystal structure analysis 761404 1.1.1.3 K205A site-directed double-primer PCR mutagenesis -, 739791 1.1.1.3 K57Aa site-directed mutagenesis, in contrast to the wild-type enzyme, the mutant enzyme shows catalytic activity with NADP+, the activity with NAD+ is increased compared to the wild-type enzyme -, 741408 1.1.1.3 K99A site-directed mutagenesis, inactive mutant. In the crystal structure, the productive geometry of the ternary complex is almost preserved with one new water molecule taking over the hydrogen bonds associated with Lys99, mutant enzyme crystal structure analysis 761404 1.1.1.3 L200F site-directed mutagenesis, compared to mutant L200F, the double mutant shows 2 degree higher optimum temperature, 1.24 times higher activity, but the same pH optimum of pH 7.5 as mutant L200F. Both mutants L200F/D215K and L200F show good resistance to organic solvents and metal ions -, 741465 1.1.1.3 L200F/D215A site-directed mutagenesis -, 741465 1.1.1.3 L200F/D215E site-directed mutagenesis -, 741465 1.1.1.3 L200F/D215G site-directed mutagenesis -, 741465 1.1.1.3 L200F/D215K site-directed mutagenesis, compared to mutant L200F, the double mutant shows 2 dgree higher optimum temperature, 1.24 times higher activity, but the same pH optimum of pH 7.5 as mutant L200F. Both mutants L200F/D215K and L200F show good resistance to organic solvents and metal ions -, 741465 1.1.1.3 additional information construction of a hom disruption mutant by insertional inactivation via double crossover leading to up to 4.3fold and 2fold increases in intracellular free L-lysine concentration and specific cephamycin C production, respectively, during stationary phase in chemically defined medium, overview -, 688167 1.1.1.3 additional information construction of a hybrid enzyme AKIII-HDHI+ by fusing a wild-type monofunctional aspartate kinase AKIII enzyme to the thrA2+ gene, encoding the homoserine dehydrogenase including the interface region of the wild-type bifunctional enzyme, the hybrid enzyme shows highly improved kinetic properties for homoserine dehydrogenase activity, and is not sensitive to L-threonine inhibition 654640 1.1.1.3 additional information construction of transgenic Arabidopsis thaliana plants by transformation with gene akthr2 via Agrobacterium tumefaciens infection, determination of expression patterns of the gene akthr1 ans akthr2 in the transgenic plants 657018 1.1.1.3 additional information design of an artificial allosteric enzyme to sense an unnatural signal for a precise and dynamical control of fluxes of growth-essential but byproduct pathways in metabolic engineering of industrial microorganisms. The natural threonine binding sites of the enzyme are engineered to a lysine binding pocket. The reengineered enzyme only responds to lysine inhibition but not to threonine 739779 1.1.1.3 additional information engineering of a Corynebacterium glutamicum strain HL1049 for effective production of methionine by elimination of the threonine synthesis gene and desensitizing the homoserine dehydrogenase versus inhibition by threonine, analysis of the amino acid spectrum of the engineered strain, overview 688822 1.1.1.3 additional information generation of a knockout homoserine dehydrogenase (HSD) mutant by chemical mutagenesis. Auxotrophic mutant formed from ddh gene, encoding diaminopimelate dehydrogenase, recombinantly expressed in Corynebacterium glutamicum strain ATCC 13032 with blocked HSD shows increased yield of L-lysine of 24.89 g/l compared to ddh gene expressed in wild-type strain ATCC 13032 (20.66 g/l of L-lysine). The maximum yield of L-lysine for the auxotrophic mutant is attained at pH 7.5 and 30°C after 96 h incubation time. Method optimization, overview -, 762359 1.1.1.3 additional information generation of HOM6-deleted (HOM6/hom6DELT and hom6DELTA/hom6DELTA) and HOM6-reintegrated (hom6DELTA/hom6DELTA::HOM6 and hom6DELTA::HOM6/hom6DELTA::HOM6) strains -, 740860 1.1.1.3 additional information heterologous expression in a hom-negative Escherichia coli mutant Gif 102, not able to grow on minimal medium unless added 1.5 mM of both L-threonine and L-methionine results in strains growing well on minimal agar plates without added threonine and methionine -, 710978 1.1.1.3 additional information key metabolic pathway for construction of an inducer-free L-homoserine-producing strain to maximize the productivity of L-homoserine based on genetic-engineering tools, comparison of L-homoserine production, cell growth, and glucose consumption in different engineered strains, overview. L-Homoserine is a nonessential amino acid for the biosynthesis of L-threonine and L-methionine. It is also an important precursor for the production of isobutanol, 1,4-butanediol, L-phosphinothricin, 2,4-ihydroxybutyrate, and 1,3-propanediol. The initial L-homoserine-producing strain HS1 is obtained by blocking the degradative and competitive pathways and overexpressing thrA (encoding homoserine dehydrogenase) based on an O-succinyl homoserine-producing strain, using the pull-push-block strategy, an efficient method to engineer microorganisms involved in biosynthesizing target products by modifying metabolic networks. L-homoserine-converting pathway-related genes (thrB, encoding homoserine kinase, and metA, encoding homoserine O-succinyltransferase) are successively deleted to block L-homoserine degradation. Gene thrA is overexpressed to push the carbon flux to L-homoserine production. Then, the lysine-auxotrophic strain HS2 is generated by deleting lysA to eliminate a precursor competing metabolic pathway on L-homoserine production. For strengthening the capability of the L-homoserine transport system and the transformation of other toxic intermediate metabolites, gene rhtA, encoding the inner membrane transporter that is involved in the export of L-homoserine, is overexpressed chromosomally by replacing the native promoter with the trc promoter to obtain strain HS3 (Trc-rhtA). The strain shows increased activity. Increase in the L-homoserine export capacity and relieve the growth burden of homoserine-producing strains to enable survival via replacement of the native promoter of the eamA gene by the trc promoter in strain HS4 (Trc-eamA). Two rhtA gene copies (the native rhtA gene and replacement of the lacI gene) and eamA are overexpressed under the trc promoter in the chromosome to construct strain HS5 (DELTAlacI::Trc-rhtA Trc-rhtA Trc-eamA). Under batch culture, strain HS5, with modification of the transport system and construction of a constitutive expression system, can produce 3.14 g/l L-homoserine, which is 54.2% higher than strain HS2 production. In addition, the specific production of strain HS5 is also increased. Repression of candidate genes by the CRISPRi system to further enhance L-homoserine production -, 760402 1.1.1.3 additional information mutant strain M20-20D is deficient in gene HOM6 and shows no activity, the defect can be complemented by recombinant expression of the Arabidopsis thaliana gene akthr2 in the mutant yeast cells 657018 1.1.1.3 additional information releasing the enzymes of the L-threonine biosynthesis pathway from feedback control and coordinating their expression plays a pivotal role in engineering Corynebacterium glutamicum into L-isoleucine producers, construction of transgenic Corynebacterium glutamicum with deregulated L-threonine biosynthesis pathway enzymes for enhanced L-isoleucine biosynthesis -, 738802 1.1.1.3 P458S site-directed mutagenesis, strain HS33/pACYC-pycP458S-thrAG433R-lysC shows increased activity (62.4% of the maximum theoretical yield) -, 760402 1.1.1.3 Q443A site-directed mutagenesis, altered reaction kinetics for both activities and altered inhibition pattern by L-threonine compared to the wild-type enzyme, asparate kinase activity is completely insensitive to inhibition by L-threonine, overview 642341 1.1.1.3 Q524A site-directed mutagenesis, altered reaction kinetics for both activities and altered inhibition pattern by L-threonine compared to the wild-type enzyme, overview 642341 1.1.1.3 R40A site-directed mutagenesis, in contrast to the wild-type enzyme, the mutant enzyme shows catalytic activity with NADP+, the activity with NAD+ is decreased compared to the wild-type enzyme -, 741408