Cloned (Comment) | Organism |
---|---|
expression of the His-tagged enzyme in Escherichia coli strain BL21(DE3) | Thermus thermophilus |
Crystallization (Comment) | Organism |
---|---|
purified recombinant enzyme, hanging drop vapour diffusion method, 0.003 ml of protein solution containing 10 mM MES-NaOH, pH 6.5, with 1 mM dithiothreitol is mixed with 0.001-0.003 ml of reservoir solution containing 0.4-0.8 M sodium malonate, pH 5.6, and 1 mM dithiothreitol, equilibration against reservoir solution at room temperature, 1 week, for enzyme-acarbose complexing the crystals are soaked in 0.5 ml of 0.8 M sodium malonate, pH 5.6, with 5 mg/ml acarbose and with or without and 4-deoxyglucose, for 30 min, X-ray diffraction structure determination and analysis at 1.9-2.5 A resolution | Thermus thermophilus |
Protein Variants | Comment | Organism |
---|---|---|
E758Q | the mutant shows highly reduced activity compared to the wild-type enzyme | Thermus thermophilus |
additional information | the deletion mutant DELTAN130 is unable to use glycogen but has high disproportionating activity with maltodextrins | Thermus thermophilus |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | initial rate kintics | Thermus thermophilus |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
additional information | Thermus thermophilus | amylomaltases are capable of the synthesis of large cyclic glucans and the disproportionation of oligosaccharides | ? | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Thermus thermophilus | O87172 | - |
- |
Purification (Comment) | Organism |
---|---|
recombinant His-tagged enzyme from Escherichia coli strain BL21(DE3) by heat treatment and nickel affinity chromatography, removal of the His-tag through cleavage with bovine thrombin | Thermus thermophilus |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
maltononaose + maltotriose = maltoundecaose + D-glucose | reaction mechanism and catalytic cycle, the catalytic nucleophile changes conformation dramatically during the reaction, Gln256 on the 250s loop is involved in orienting the substrate in the +1 site. The absence of a suitable base in the covalent intermediate structure explains the low hydrolysis activity, overview | Thermus thermophilus |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
0.0027 | - |
mutant E758Q | Thermus thermophilus |
5.19 | - |
wild-type enzyme | Thermus thermophilus |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
additional information | amylomaltases are capable of the synthesis of large cyclic glucans and the disproportionation of oligosaccharides | Thermus thermophilus | ? | - |
? | |
additional information | glucose transfer/production using maltose and glycogen. Wild-type DPE2 can bind to starch and glycogen has very little, if any, ability to dissociate DPE2 from the starch pellet | Thermus thermophilus | ? | - |
? |
Synonyms | Comment | Organism |
---|---|---|
alpha-amylase-like transglycosylase | - |
Thermus thermophilus |
amylomaltase | - |
Thermus thermophilus |
More | amylomaltases are glycosyl hydrolases belonging to glycoside hydrolase family 77 | Thermus thermophilus |