Cloned (Comment) | Organism |
---|---|
expression of N-and C-terminally His6-tagged component E1b and mutants, and of C-terminally His-tagged lipoic acid-bearing domain, amino acid residues 1-84 of component E2b, in vitro lipoylation of the latter | Homo sapiens |
Crystallization (Comment) | Organism |
---|---|
purified wild-type and C-terminally His-tagged recombinant E1b component and mutants, 22°C, hanging drop vapour diffusion method, Mg2+ or Mn2+, X-ray diffraction structure determination and analysis at 1.8 A resolution | Homo sapiens |
Protein Variants | Comment | Organism |
---|---|---|
D295A | site-directed mutagenesis of an alpha-subunit residue of component E1b, increased activity compared to the wild-type | Homo sapiens |
R287A | site-directed mutagenesis of an alpha-subunit residue of component E1b, highly increased Km and reduced activity compared to the wild-type | Homo sapiens |
R301A | site-directed mutagenesis of an alpha-subunit residue of component E1b, increased Km and reduced activity compared to the wild-type | Homo sapiens |
Y300A | site-directed mutagenesis of an alpha-subunit residue of component E1b, increased Km and reduced activity compared to the wild-type | Homo sapiens |
Y300F | site-directed mutagenesis of an alpha-subunit residue of component E1b, increased Km and reduced activity compared to the wild-type | Homo sapiens |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | kinetics of the overall reaction, thermodynamics and dissociation constants of interaction between component E1b and the lipoic acid-bearing domain of component E2b | Homo sapiens | |
0.007 | - |
thiamine diphosphate | recombinant wild-type component E1b, pH 7.5, 22°C | Homo sapiens | |
0.017 | - |
thiamine diphosphate | recombinant component E1b mutant D295Aalpha, pH 7.5, 22°C | Homo sapiens | |
0.024 | - |
thiamine diphosphate | recombinant component E1b mutant R287Aalpha, pH 7.5, 22°C | Homo sapiens | |
0.029 | - |
thiamine diphosphate | recombinant component E1b mutants R301Aalpha and Y300Falpha, pH 7.5, 22°C | Homo sapiens | |
0.04 | - |
thiamine diphosphate | recombinant component E1b mutant Y300Aalpha, pH 7.5, 22°C | Homo sapiens | |
0.05 | - |
2-oxo-isovalerate | recombinant wild-type component E1b, and mutant D295Aalpha, pH 7.5, 22°C | Homo sapiens | |
0.23 | - |
2-oxo-isovalerate | recombinant component E1b mutant R301Aalpha, pH 7.5, 22°C | Homo sapiens | |
0.25 | - |
2-oxo-isovalerate | recombinant component E1b mutant Y300Falpha, pH 7.5, 22°C | Homo sapiens | |
0.34 | - |
2-oxo-isovalerate | recombinant component E1b mutant Y300Aalpha, pH 7.5, 22°C | Homo sapiens | |
2.33 | - |
2-oxo-isovalerate | recombinant component E1b mutant R287Aalpha, pH 7.5, 22°C | Homo sapiens |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Mg2+ | required for the binding of cofactor thiamine diphosphate to component E1b, Mn2+ can substitute | Homo sapiens |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
3-methyl-2-oxobutanoate + [dihydrolipoyllysine-residue(2-methylpropanoyl)transferase]-lipoyllysine | Homo sapiens | - |
[dihydrolipoyllysine-residue (2-methylpropanoyl)transferase] S-(2-methylpropanoyl)dihydrolipoyllysine + CO2 | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Homo sapiens | - |
- |
- |
Posttranslational Modification | Comment | Organism |
---|---|---|
additional information | limited proteolytic analysis of E1b component, overview | Homo sapiens |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
3-methyl-2-oxobutanoate + [dihydrolipoyllysine-residue (2-methylpropanoyl)transferase] lipoyllysine = [dihydrolipoyllysine-residue (2-methylpropanoyl)transferase] S-(2-methylpropanoyl)dihydrolipoyllysine + CO2 + 2 H+ | substrate recognition and reaction mechanism | Homo sapiens |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
additional information | - |
decarboxylation activity, 30°C | Homo sapiens |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
2-oxoisovalerate + [dihydrolipoyllysine-residue(2-methylpropanoyl)transferase]-lipoyllysine | - |
Homo sapiens | ? + CO2 | - |
? | |
3-methyl-2-oxobutanoate + [dihydrolipoyllysine-residue(2-methylpropanoyl)transferase]-lipoyllysine | - |
Homo sapiens | [dihydrolipoyllysine-residue (2-methylpropanoyl)transferase] S-(2-methylpropanoyl)dihydrolipoyllysine + CO2 | - |
? | |
additional information | the overall reaction proceeds in several steps of the components E1, E2, and E3, overview, conformation of the conserved phosphorylation loop, carrying 2 phosphorylation sites Ser292alpha andSer302alpha, is essential for recognition of lipoylated LBD to initiate E1b-catalyzed reductive acylation, E1b is regulated by reversible phosphorylation through the kinase of the multienzyme complex | Homo sapiens | ? | - |
? |
Synonyms | Comment | Organism |
---|---|---|
BCKD | - |
Homo sapiens |
branched-chain alpha-keto acid decarboxylase/dehydrogenase | - |
Homo sapiens |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.195 | - |
2-oxo-isovalerate | recombinant wild-type component E1b, pH 7.5, 22°C | Homo sapiens | |
0.197 | - |
thiamine diphosphate | recombinant wild-type component E1b, pH 7.5, 22°C | Homo sapiens | |
0.31 | - |
thiamine diphosphate | recombinant component E1b mutant Y300Aalpha, pH 7.5, 22°C | Homo sapiens | |
0.36 | - |
2-oxo-isovalerate | recombinant component E1b mutant Y300Aalpha, pH 7.5, 22°C | Homo sapiens | |
0.38 | - |
2-oxo-isovalerate | recombinant component E1b mutant R287Aalpha, pH 7.5, 22°C | Homo sapiens | |
0.39 | - |
thiamine diphosphate | recombinant component E1b mutant R287Aalpha, pH 7.5, 22°C | Homo sapiens | |
0.41 | - |
2-oxo-isovalerate | recombinant component E1b mutant R301Aalpha, pH 7.5, 22°C | Homo sapiens | |
0.42 | - |
thiamine diphosphate | recombinant component E1b mutants R301Aalpha and D295Aalpha, pH 7.5, 22°C | Homo sapiens | |
0.485 | - |
2-oxo-isovalerate | recombinant component E1b mutant D295Aalpha, pH 7.5, 22°C | Homo sapiens | |
0.53 | - |
thiamine diphosphate | recombinant component E1b mutant Y300Falpha, pH 7.5, 22°C | Homo sapiens | |
0.57 | - |
2-oxo-isovalerate | recombinant component E1b mutant Y300Falpha, pH 7.5, 22°C | Homo sapiens |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.5 | - |
assay at | Homo sapiens |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
thiamine diphosphate | bound to component E1, heterotetrameric cofactor binding fold, cofactor binding prevents phosphorylation of E1b and inactivates it by inducing a disorder-to-order transition of the conserved phosphorylation loop carrying 2 phosphorylation sites Ser292alpha andSer302alpha, cross-talk between thiamine diphosphate and the phosphorylation loop conformation as a feed-forward switch for th complex reaction | Homo sapiens |