1.2.4.4 D108N less thermostable than wild type enzyme 687543 1.2.4.4 D200A less thermostable than wild type enzyme 687543 1.2.4.4 D200A/D108N the mutant is defective in folding and assembly and as no detectable overall activity 687543 1.2.4.4 D200N less thermostable than wild type enzyme 687543 1.2.4.4 D295A site-directed mutagenesis of an alpha-subunit residue of component E1b, increased activity compared to the wild-type 656230 1.2.4.4 D296A inactive enzyme, no ability of component E1 apoenzyme to reconstitute with thiamine diphosphate 349090 1.2.4.4 E198Q/D200N the mutant is defective in folding and assembly and as no detectable overall activity 687543 1.2.4.4 F364C E1alpha-missense mutation in type IA maple syrup urine disease that causes the occurence of exclusively alpha,beta dimers 349091 1.2.4.4 H146A site-directed mutagenesis, mutation of a beta'-subunit residue, no reductive acylation activity, low decarboxylation activity 656171 1.2.4.4 H147N site-directed mutagenesis, mutation of a beta'-subunit residue, no reductive acylation activity, low decarboxylation activity 656171 1.2.4.4 H291A site-directed mutagenesis, mutation of a alpha-subunit residue, highly reduced activity compared to the wild-type E1b component 656171 1.2.4.4 H291N site-directed mutagenesis, mutation of a alpha-subunit residue, highly reduced activity compared to the wild-type E1b component 656171 1.2.4.4 H291Q site-directed mutagenesis, mutation of a alpha-subunit residue, highly reduced activity compared to the wild-type E1b component 656171 1.2.4.4 H292A inactive enzyme, no binding of thiamine diphosphate 349090 1.2.4.4 additional information complete deletion of the bkdR open reading frame, produces fewer spores or the spores have reduced viability, is apparently not complemented in trans by the wild-type allele, is able to utilize leucine as sole carbon source and has no detectable growth defect, bkdR gene product acts as a repressor, rather than an activator of transcription 674248 1.2.4.4 additional information construction of transgenic Arabidopsis thaliana plants overexpressing the branched-chain alpha-keto acid dehydrogenase multienzyme complex BCKDC in chloroplasts via Agrobacterium tumefaciens transformation under control of the CaMV 35S promotor, accumulation of branched-chain acyl-CoAs and alteration of free amino acid composition in seeds, overview 657104 1.2.4.4 additional information enzyme complex regulation by reversible phosphorylation is impaired in component E1b S292 and S302 mutants, no or residual acylation of the lipoic acid-bearing domain of component E2b, overview 657370 1.2.4.4 additional information hE1b-Tyr113Phe mutant, specifically affects the decarboxylation reaction, thiamine diphosphate appears hyperactive, is prone to paracatalytic inactivation 677159 1.2.4.4 additional information missense mutation in E1b subunits that cause maple syrup urine disease: R114W-alpha, T166M-alpha, R220W-alpha. N222S-alpha. M64T-alpha. G204S-alpha. A208T-alpha. T265R-alpha, I281T-alpha, N126Y-beta, Q145K-alpha, H156R-beta, A209D-alpha, A240P-alpha. G245R-alpha, R252H-alpha, F364C-alpha, Y368C-alpha and Y393N-alpha 349040 1.2.4.4 additional information the hybrid E1b heterotetramer carrying one wild type, one S292Qalpha subunit, and two wild type beta subunits contains only one functional active site and exhibits nearly 40% of the wild type activity 687543 1.2.4.4 R287A site-directed mutagenesis of an alpha-subunit residue of component E1b, highly increased Km and reduced activity compared to the wild-type 656230 1.2.4.4 R288A inactive enzyme, no detectable phosphorylation 349090 1.2.4.4 R301A site-directed mutagenesis of an alpha-subunit residue of component E1b, increased Km and reduced activity compared to the wild-type 656230 1.2.4.4 S292D site-directed mutagenesis, mutation of a alpha-subunit residue of complex component E1b, reduced activity compared to the wild-type E1b component 657370 1.2.4.4 S292E site-directed mutagenesis, mutation of a alpha-subunit residue of complex component E1b, highly reduced activity compared to the wild-type E1b component 657370 1.2.4.4 S292N site-directed mutagenesis, mutation of a alpha-subunit residue of complex component E1b, reduced activity compared to the wild-type E1b component 657370 1.2.4.4 S292Q no activity 687543 1.2.4.4 S292Q site-directed mutagenesis, mutation of a alpha-subunit residue of complex component E1b, inactive mutant 657370 1.2.4.4 S293A 10fold increased Km-value for 3-methyl-2-oxobutanoate, 2.8fold increased Km-value for 4-methyl-2-oxopentanoate, no change in Km-value for thiamine diphosphate 349090 1.2.4.4 S293A mutation in the alpha-subunit, nearly 12fold increase in Km-value, no inactivation after incubation with ATP 349085 1.2.4.4 S293E mutation in the alpha-subunit, completely inactive enzyme 349085 1.2.4.4 S293E no ability of the E1 apoenzyme to reconstitute with thiamine diphosphate 349090 1.2.4.4 S293E/S303E mutation in the alpha-subunit, no activity 349085 1.2.4.4 S302A site-directed mutagenesis, mutation of a alpha-subunit residue of complex component E1b, increased activity compared to the wild-type E1b component 657370 1.2.4.4 S303A mutation in the alpha-subunit, no effect upon enzyme activity 349085 1.2.4.4 S303E mutation in the alpha-subunit, no effect upon enzyme activity 349085 1.2.4.4 S313A twofold increase in Km-value but no change in turnover-number 349086 1.2.4.4 S315A mutation has no effect on Km-value or turnover-number 349086 1.2.4.4 S319A mutation has no effect on Km-value or turnover-number 349086 1.2.4.4 T265R missense mutation in type IA maple syrup urine disease that causes the occurence of both alpha2beta2 tetramers and lower molecular weight species 349091 1.2.4.4 Y300A site-directed mutagenesis of an alpha-subunit residue of component E1b, increased Km and reduced activity compared to the wild-type 656230 1.2.4.4 Y300F site-directed mutagenesis of an alpha-subunit residue of component E1b, increased Km and reduced activity compared to the wild-type 656230 1.2.4.4 Y368C missense mutation in type IA maple syrup urine disease that causes the occurence of both alpha2beta2 tetramers and lower molecular weight species 349091 1.2.4.4 Y393N E1alpha-missense mutation in type IA maple syrup urine disease that causes the occurence of exclusively alpha,beta dimers 349091