Cloned (Comment) | Organism |
---|---|
both catalytic domains of the enzyme, performing each one of the enzyme activities, are expressed separately with or without the interface region, resulting in increased activity of each domain compared to the wild-type bifunctional holoenzyme, the isolated catalytic domains are no longer allosterically regulated, expression of hybrid holoenzyme AKIII-HDHI+ | Escherichia coli |
Protein Variants | Comment | Organism |
---|---|---|
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 | Escherichia coli |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.41 | - |
L-homoserine | recombinant hybrid bifunctional holoenzyme AKIII-HDHI+ containing the interface region, homoserine dehydrogenase activity | Escherichia coli | |
0.68 | - |
L-homoserine | recombinant isolated catalytic HDH-domain containing the interface region, homoserine dehydrogenase activity | Escherichia coli | |
1.2 | - |
L-homoserine | recombinant wild-type bifunctional holoenzyme, homoserine dehydrogenase activity | Escherichia coli | |
17.2 | - |
L-homoserine | recombinant isolated catalytic HDH-domain not containing the interface region, homoserine dehydrogenase activity | Escherichia coli |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
L-aspartate 4-semialdehyde + NADPH | Escherichia coli | part of the aspartate pathway of amino acid biosynthesis | L-homoserine + NADP+ | - |
r |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Escherichia coli | - |
- |
- |
Purification (Comment) | Organism |
---|---|
recombinant separated catalytic domains | Escherichia coli |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
L-homoserine + NAD(P)+ = L-aspartate 4-semialdehyde + NAD(P)H + H+ | bifunctional enzyme showing aspartate kinase, EC 2.7.2.4, and homoserine dehydrogenase activities | Escherichia coli |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
L-aspartate 4-semialdehyde + NADPH | - |
Escherichia coli | L-homoserine + NADP+ | - |
r | |
L-aspartate 4-semialdehyde + NADPH | part of the aspartate pathway of amino acid biosynthesis | Escherichia coli | L-homoserine + NADP+ | - |
r |
Synonyms | Comment | Organism |
---|---|---|
AK-HDH | - |
Escherichia coli |
aspartokinase-homoserine dehydrogenase I | - |
Escherichia coli |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.24 | - |
L-homoserine | recombinant wild-type bifunctional holoenzyme, homoserine dehydrogenase activity | Escherichia coli | |
0.51 | - |
L-homoserine | recombinant isolated catalytic HDH-domain not containing the interface region, homoserine dehydrogenase activity | Escherichia coli | |
3.3 | - |
L-homoserine | recombinant isolated catalytic HDH-domain containing the interface region, homoserine dehydrogenase activity | Escherichia coli | |
24 | - |
L-homoserine | recombinant hybrid bifunctional holoenzyme AKIII-HDHI+ containing the interface region, homoserine dehydrogenase activity | Escherichia coli |