2.7.1.39	A20G	site-directed mutagenesis, the mutant retains wild-type enzymatic activity, with dramatically decreased feedback inhibition by L-threonine. The changes in L-threonine affinity to the CglThrB-A20G active site derive from loss of van der Waals interactions	-, 758579	
2.7.1.39	A20L	site-directed mutagenesis	-, 758579	
2.7.1.39	A20S	site-directed mutagenesis	-, 758579	
2.7.1.39	A20V	site-directed mutagenesis	-, 758579	
2.7.1.39	H139L	mutant enzyme with diminished kinase activity and ATPase activity 150fold greater than that of the wild-type enzyme	641471	
2.7.1.39	H202L	Km-value for L-homoserine and ATP remain unchanged, the Ki-value for substrate inhibition by L-homoserine increases about 8fold, the turnover-number decreases by 50%,unlike the wild-type enzyme the L-homoserine ethyl, isopropyl, and n-propyl esters show substrate inhibition	641471	
2.7.1.39	H205Q	Km-value for ATP remains unchanged, ATPase activity is within a factor 2 of the wild-type enzyme, the kinase activity is less than 0.03% that of the wild-type enzyme	641471	
2.7.1.39	additional information	engineering of Corynebacterium glutamicum to increase production of L-threonine, the attempt is to render the active site of Corynebacterium glutamicum ThrB (CglThrB) more selective toward L-homoserine than L-threonine	-, 758579	
2.7.1.39	additional information	expression in Solanum tuberosum plant with targeting to chloroplast and cytosol. Both approaches result in up to 11fold increase in total enzyme activity. Transgenic plants exhibit reduced homoserine levels while methionine and threonine do not accumulate significantly. Plants with elevated levels of cytosolic enzyme exhibit a reduction in transcript levels of the endogenous homoserine kinase, as well as of threonine synthase, cystathionine beta-lyase, and methionine synthase. In all plants, cystathionine gamma-synthase expression remains unchanged, while S-adenosylmethionine synthetase expression increases. Excess of plastidial localized homoserine kinase does not influence the de novo synthesis of methionine and threonine	690392	
2.7.1.39	additional information	gene is essential for growth in rich media, when ammonium is the nitrogen source, or when threonine is supplied as an amino acid instead of a dipeptide. the severity of the growth defect associated with THR1 repression increases with increasing incubation temperature	694038