EC Number   |
Protein Variants |
Reference |
|---|
  2.3.1.276 | H308A |
specific activity is 7.7% compared to the wild-type enzyme |
729696 |
| 2.3.1.276 | K340A |
specific activity is 63.3% compared to the wild-type enzyme |
729696 |
| 2.3.1.276 | K377A |
specific activity is 82.6% compared to the wild-type enzyme |
729696 |
| 2.3.1.276 | more |
C-terminal deletion mutants DC005 and DC011 (deletion of the C-terminal 5 or 11 residues of the ST0452 protein) shows 20% and 38% less galactosamine-1-phosphate acetyltransferase activity than the wild-type ST0452 protein. The mutant enzyme DC011 (deletion of the C-terminal 11 residues of the ST0452 protein) shows little thermal stability at 80°C. The C-terminal domain of the ST0452 protein, with its LbetaH structure, appears to be essential for the formation of its trimeric form and, in turn, the high stability of the entire ST0452 protein. The deletion mutant enzymes DC021, DC031, DC041, DC071 and DC121, are produced in an insoluble form or aggregated immediately after purification. Mutant enzymes DC051 and DC171 can be expressed in a soluble form. Mutant enzyme DC051 becomes completely insoluble after 5 min treatment at 60°C, while mutant enzyme DC171 is insoluble after 5 min treatment at 70 °C |
729696 |
| 2.3.1.276 | N331A |
specific activity is 3.1% compared to the wild-type enzyme |
729696 |
| 2.3.1.276 | T80S/Y97N |
the mutant enzyme shows 6.5times-higher activity, compared to that of the wild-type ST0452 protein, revealing that these two substituted residues function cooperatively to increase N-acetylglucosamine-1-phosphate uridyltransferase activity |
746844 |
| 2.3.1.276 | Y311A |
specific activity is 3.3% compared to the wild-type enzyme |
729696 |
| 2.3.1.276 | Y97N |
the mutant enzyme exhibits over 4 times higher N-acetylglucosamine-1-phosphate uridyltransferase activity, compared with that of the wild-type ST0452 protein. The three-dimensional structure of the Y97N protein was not changed by this substitution but the interactions with the substrate were slightly modified, which might cause the activity to increase. The crystal structure of the Y97N protein shows that positions 146 (Glu) and 80 (Thr) form interactions with GlcNAc, and an engineering strategy is applied to these residues to increase activity |
-, 746844 |
