EC Number   |
Protein Variants |
Reference |
|---|
   3.2.1.B26 | D406G |
inactive mutant |
715512 |
| 3.2.1.B26 | D458G |
inactive mutant |
715512 |
| 3.2.1.B26 | D462G |
inactive mutant. Addition of 1 mM NaN3 rescues enzymatic activity using 2-nitrophenyl-beta-D-glucopyranoside as substrate. Activity is 7fold lower compared to wild-type |
715512 |
| 3.2.1.B26 | delHis489 |
mutation produces faster enzyme inactivation, kcat/KM for 2-nitrophenyl beta-D-galactopyranoside is 45% of the wild-type value |
721007 |
| 3.2.1.B26 | delVal484-His489 |
clone DELTA6 lacks the last six amino acids (-Val-Lys-Pro-Leu-Arg-His-COOH) and has no additional mutations. Mutation produces faster enzyme inactivation, kcat/KM for 2-nitrophenyl beta-D-galactopyranoside is 37% of the wild-type value |
721007 |
| 3.2.1.B26 | E206Q |
mutant shows 10- and 60-fold reduced activities on aryl-galacto and aryl-glucosides, respectively, when compared with the wild type. Significant decrease in Km-value with 4-nitrophenyl beta-D-glucoside or 2-nitrophenyl beta-D-glucoside. The residual activity of the mutant loses the typical pH dependence shown by the wild type. These data suggest that Glu206 acts as the general acid/base catalyst in the hydrolysis reaction |
-, 720966 |
| 3.2.1.B26 | E206Q |
mutant shows 10- and 60-fold reduced activities on aryl-galacto and aryl-glucosides, respectively, when compared with the wild type. Significant decrease in Km-value with 4-nitrophenyl beta-D-glucoside or 2-nitrophenyl betaD-glucoside. The residual activity of the mutant loses the typical pH dependence shown by the wild type. These data suggest that Glu206 acts as the general acid/base catalyst in the hydrolysis reaction |
-, 720966 |
| 3.2.1.B26 | E335G |
inactive mutant |
715512 |
| 3.2.1.B26 | E386G |
mutation in nucleophile residue E387, mutation completely abolishes activity under statndard conditions. The addition of 2 M sodium formate as an external nucleophile leads to the recovery of 8.40% activity with accumulation of oligosaccharides. At pH 3.0 and low concentrations of sodium formate buffer, the hyperthermophilic glycosynthase shows kcat values similar to those of the wild-type and 17fold higher than those observed at the usual reactivation conditions in 2 M sodium formate at pH 6.5 |
735665 |
| 3.2.1.B26 | E387A |
inactive mutant enzyme of the catalytic nucleophile Glu387 is restored by externally added nucleophiles (sodium azide and sodium formate) |
724259 |
