General Stability | Organism |
---|---|
2-mercaptoethanol stabilizes the enzyme | Escherichia coli |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
1,2,4-Triazole-3-alanine | - |
Escherichia coli | |
D-histidine | - |
Escherichia coli | |
diphosphate | weak | Escherichia coli | |
L-histidinol | - |
Escherichia coli | |
Mg2+ | inhibition at 15 mM, optimal activation at 5-10 mM | Escherichia coli | |
N-Acetylhistidine | - |
Escherichia coli | |
NEM | - |
Escherichia coli | |
p-chloromercuribenzoate | L-His, ATP, and Mg2+ protect | Escherichia coli |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Mg2+ | optimal concentration: 5-10 mM, inhibition at 15 mM | Escherichia coli |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
42500 | - |
2 * 42500, SDS-PAGE | Escherichia coli |
85000 | - |
gel filtration | Escherichia coli |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Escherichia coli | - |
K12 | - |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
ATP + L-histidine + tRNAHis = AMP + diphosphate + L-histidyl-tRNAHis | two molecules of ATP and histidine are bound per molecule of enzyme | Escherichia coli |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
121.8 | - |
- |
Escherichia coli |
Storage Stability | Organism |
---|---|
-20°C, 50% glycerol, 5 mM 2-mercaproethanol, stable for more than 4 months | Escherichia coli |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + L-histidine + tRNAHis | - |
Escherichia coli | AMP + diphosphate + L-histidyl-tRNAHis | - |
? |
Subunits | Comment | Organism |
---|---|---|
dimer | 2 * 42500, SDS-PAGE | Escherichia coli |
More | at temperatures above 25 C, the enzyme tends to aggregate giving forms with a MW 90000 and 175000 | Escherichia coli |
Temperature Stability Minimum [°C] | Temperature Stability Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
in presence of 2-mercaptoethanol stable for 5 h, 40% loss of activity after 12 h. In absence of 2-mercaptoethanol total loss of activity in a few min | Escherichia coli |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.4 | - |
histidyl-tRNA formation | Escherichia coli |
8 | 9 | histidine-dependent ATP-diphosphate exchange | Escherichia coli |