Protein Variants | Comment | Organism |
---|---|---|
H139L | mutant enzyme with diminished kinase activity and ATPase activity 150fold greater than that of the wild-type enzyme | Escherichia coli |
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 | Escherichia coli |
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 | Escherichia coli |
R234C | no observable homoserine kinase activity, the ATPase activity is nearly 20 times that of the wild-type enzyme at pH 8.0. 7fold increase in Km-value for ATP. Mutant enzyme is sensitive to heat treatment and begins to precipitate at 55°C | Escherichia coli |
R234H | mutant enzyme has a diminished kinase activity, 0.4% of that of the wild-type enzyme, and an enhanced ATPase activity, Km-values for both substrates are unchanged | Escherichia coli |
R234L | Km-value for L-homoserine increases nearly 300fold, the turnover-number decreases by 90fold compared to the wild-type enzyme. Less than a 2fold change in Km for ATP, the inherent ATPase activity increases by 3fold. The mutant enzyme has turnover-numbers for homoserine esters that are only 10% that of homoserine, but has higher affinity for the esters than for L-homoserine itself. L-Cys, a strong inhibitor of the wild-type enzyme, is 50fold less effective as inhibitor of the mutant enzyme. L-Thr no longer inhibits the mutant enzyme. Unlike the wild-type enzyme, addition of 10 mM L-homoserine to the mutant enzyme has no protective effect on the number of arginyl residues titrated with (p-hydroxyphenyl)glyoxal | Escherichia coli |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
(4R)-4-hydroxypentan-2-one | - |
Escherichia coli | |
(p-hydroxyphenyl)-glyoxal | - |
Escherichia coli | |
2-amino-3-(phosphonoethyl)thiopropionate | - |
Escherichia coli | |
2-Amino-5-phosphonovalerate | - |
Escherichia coli | |
2-amino-5-phosphovalerate | - |
Escherichia coli | |
L-2-amino-5-hydroxyvalerate | substrate inhibition | Escherichia coli | |
L-Cys | - |
Escherichia coli | |
L-Glutamic acid | - |
Escherichia coli | |
L-homoserine | - |
Escherichia coli | |
L-homoserine alpha-methyl ester | substrate inhibition | Escherichia coli | |
L-homoserine ethyl ester | unlike the wild-type enzyme the mutant enzyme H202L is inhibited | Escherichia coli | |
L-homoserine isopropyl ester | unlike the wild-type enzyme the mutant enzyme H202L is inhibited | Escherichia coli | |
L-homoserine n-propyl ester | unlike the wild-type enzyme the mutant enzyme H202L is inhibited | Escherichia coli | |
L-norvaline | - |
Escherichia coli | |
L-Thr | substrate inhibition | Escherichia coli | |
O-phospho-L-serine | - |
Escherichia coli |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.11 | - |
ATP | mutant enzyme H202L | Escherichia coli | |
0.11 | - |
L-homoserine | mutant enzyme H202L | Escherichia coli | |
0.13 | - |
ATP | wild-type enzyme | Escherichia coli | |
0.13 | - |
ATP | mutant enzyme R234H | Escherichia coli | |
0.13 | - |
L-homoserine | mutant enzyme R234H | Escherichia coli | |
0.14 | - |
L-homoserine | wild-type enzyme | Escherichia coli | |
0.15 | - |
ATP | mutant enzyme H205Q | Escherichia coli | |
0.21 | - |
ATP | mutant enzyme R234L | Escherichia coli | |
0.28 | - |
L-aspartate beta-semialdehyde | wild-type enzyme | Escherichia coli | |
0.49 | - |
ATP | mutant enzyme H139L | Escherichia coli | |
0.88 | - |
ATP | mutant enzyme R234C | Escherichia coli | |
1.1 | - |
L-2-amino-5-hydroxyvalerate | wild-type enzyme | Escherichia coli | |
1.2 | - |
L-homoserine isopropyl ester | wild-type enzyme | Escherichia coli | |
1.9 | - |
L-homoserine ethyl ester | wild-type enzyme | Escherichia coli | |
2.5 | - |
L-homoserine | mutant enzyme H139L | Escherichia coli | |
3.5 | - |
L-homoserine n-propyl ester | wild-type enzyme | Escherichia coli | |
3.7 | - |
L-homoserine | mutant enzyme H205Q | Escherichia coli | |
4.9 | - |
L-homoserine methyl ester | wild-type enzyme | Escherichia coli | |
5.8 | - |
L-homoserine n-butyl ester | wild-type enzyme | Escherichia coli | |
6.2 | - |
L-homoserine | mutant enzyme R234H | Escherichia coli | |
6.9 | - |
L-homoserine | wild-type enzyme | Escherichia coli | |
6.9 | - |
L-homoserine isobutyl ester | wild-type enzyme | Escherichia coli | |
8.5 | - |
L-homoserine | mutant enzyme R234C | Escherichia coli | |
11.6 | - |
L-2-amino-1,4-butanediol | wild-type enzyme | Escherichia coli | |
31.8 | - |
D-homoserine | wild-type enzyme | Escherichia coli | |
40.1 | - |
L-homoserine | mutant enzyme R234L | Escherichia coli | |
58.2 | - |
L-homoserine | mutant enzyme H202L | Escherichia coli |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + L-homoserine | Escherichia coli | enzyme in the aspartate pathway of amino acid biosynthesis | ADP + O-phospho-L-homoserine | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Escherichia coli | - |
- |
- |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + D-homoserine | 32% of the turnover number with L-homoserine | Escherichia coli | ADP + O-phospho-D-homoserine | - |
? | |
ATP + L-2-amino-1,4-butanediol | 7.9% of the turnover number with L-homoserine | Escherichia coli | ADP + ? | - |
? | |
ATP + L-2-amino-5-hydroxyvalerate | 9.9% of the turnover number with L-homoserine | Escherichia coli | ADP + L-2-amino-5-phosphovalerate | - |
? | |
ATP + L-aspartate 4-semialdehyde | 8.2% of the turnover number with L-homoserine | Escherichia coli | ? | - |
? | |
ATP + L-homoserine | - |
Escherichia coli | ADP + O-phospho-L-homoserine | - |
? | |
ATP + L-homoserine | enzyme in the aspartate pathway of amino acid biosynthesis | Escherichia coli | ADP + O-phospho-L-homoserine | - |
? | |
ATP + L-homoserine ethyl ester | 74% of the turnover number with L-homoserine | Escherichia coli | ADP + O-phospho-L-homoserine ethyl ester | - |
? | |
ATP + L-homoserine isopropyl ester | 74% of the turnover number with L-homoserine | Escherichia coli | ADP + O-phospho-L-homoserine isopropyl ester | - |
? | |
ATP + L-homoserine isubutyl ester | 84% of the turnover number with L-homoserine | Escherichia coli | ADP + O-phospho-L-homoserine isobutyl ester | - |
? | |
ATP + L-homoserine methyl ester | 80% of the turnover number with L-homoserine | Escherichia coli | ADP + O-phospho-L-homoserine methyl ester | - |
? | |
ATP + L-homoserine n-butyl ester | 160% of the turnover number with L-homoserine | Escherichia coli | ADP + O-phospho-L-homoserine n-butyl ester | - |
? | |
ATP + L-homoserine n-propyl ester | 76% of the turnover number with L-homoserine | Escherichia coli | ADP + O-phospho-L-homoserine n-propyl ester | - |
? | |
additional information | enzyme has inherent ATPase activity | Escherichia coli | ? | - |
? |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.007 | - |
L-homoserine butyl ester | mutant R234L | Escherichia coli | |
0.0111 | - |
L-homoserine propyl ester | mutant R234L | Escherichia coli | |
0.018 | - |
L-homoserine methyl ester | mutant R234L | Escherichia coli | |
0.021 | - |
L-homoserine ethyl ester | mutant R234L | Escherichia coli | |
0.2 | - |
L-homoserine | mutant R234L | Escherichia coli | |
2 | - |
L-2-amino-1,4-butanediol | wild-type enzyme | Escherichia coli | |
2.1 | - |
L-aspartate beta-semialdehyde | wild-type enzyme | Escherichia coli | |
2.5 | - |
L-2-amino-5-hydroxyvalerate | wild-type enzyme | Escherichia coli | |
2.5 | - |
L-homoserine butyl ester | mutant H202L | Escherichia coli | |
2.7 | - |
L-homoserine propyl ester | mutant H202L | Escherichia coli | |
3.3 | - |
D-homoserine | wild-type enzyme | Escherichia coli | |
4.1 | - |
L-homoserine ethyl ester | mutant H202L | Escherichia coli | |
5.4 | - |
L-homoserine methyl ester | mutant H202L | Escherichia coli | |
9.1 | - |
L-homoserine | mutant H202L | Escherichia coli | |
13.6 | - |
L-homoserine ethyl ester | wild-type enzyme | Escherichia coli | |
13.6 | - |
L-homoserine isopropyl ester | wild-type enzyme | Escherichia coli | |
14 | - |
L-homoserine n-propyl ester | wild-type enzyme | Escherichia coli | |
14.7 | - |
L-homoserine methyl ester | wild-type enzyme | Escherichia coli | |
16.4 | - |
L-homoserine isobutyl ester | wild-type enzyme | Escherichia coli | |
18.3 | - |
L-homoserine | wild-type enzyme | Escherichia coli | |
29.1 | - |
L-homoserine n-butyl ester | wild-type enzyme | Escherichia coli |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
8 | - |
wild-type enzyme | Escherichia coli |
Ki Value [mM] | Ki Value maximum [mM] | Inhibitor | Comment | Organism | Structure |
---|---|---|---|---|---|
0.2 | 0.5 | L-norvaline | wild-type enzyme | Escherichia coli | |
0.2 | 0.5 | L-Glutamic acid | wild-type enzyme | Escherichia coli | |
0.2 | 0.5 | (4R)-4-hydroxypentan-2-one | wild-type enzyme | Escherichia coli | |
0.3 | - |
L-Thr | wild-type enzyme | Escherichia coli | |
0.3 | - |
2-amino-3-(phosphonoethyl)thiopropionate | wild-type enzyme | Escherichia coli | |
0.46 | - |
L-Cys | wild-type enzyme | Escherichia coli | |
2.7 | - |
O-phospho-L-serine | - |
Escherichia coli | |
10.4 | - |
2-amino-5-phosphovalerate | - |
Escherichia coli |