EC Number |
Protein Variants |
Reference |
---|
4.3.1.18 | C400A |
dehydratase activity is completely abolished. Km (beta-chloro-D-alanine) decreased in native and Zn2+-depleted form compared to wild-type. kcat (beta-chloro-D-alanine) increased in native and Zn2+-depleted form compared to wild-type |
729705 |
4.3.1.18 | D236L |
compared to wild-type enzyme and to mutant enzyme T166A the D236L mutant has a lower affinity for pyridoxal 5'-phosphate |
747007 |
4.3.1.18 | G279D |
mutant G279D and G281D, loss of activity, the mutant enzymes form a Schiff base linkage with pyridoxal 5'-phosphate but do not hold the cofactor in a catalytically competent orientation. G279D has 225fold reduced cofactor affinity, the ability to retain a cofactor:glycine complex is decreased 765fold. Mutant G281D has 50fold decreased cofactor affinity, the ability to retain a cofactor:glycine complex is decreased 1970fold |
210814 |
4.3.1.18 | G281D |
mutant G279D and G281D, loss of activity, the mutant enzymes form a Schiff base linkage with pyridoxal 5'-phosphate but do not hold the cofactor in a catalytically competent orientation. G279D has 225fold reduced cofactor affinity, the ability to retain a cofactor:glycine complex is decreased 765fold. Mutant G281D has 50fold decreased cofactor affinity, the ability to retain a cofactor:glycine complex is decreased 1970fold |
210814 |
4.3.1.18 | H398A |
dehydratase activity is completely abolished, kcat (D-serine) highly decreased. Km (beta-chloro-D-alanine) decreased in native and Zn2+-depleted form compared to wild-type. kcat (beta-chloro-D-alanine) increased in native and Zn2+-depleted form compared to wild-type |
729705 |
4.3.1.18 | K57A |
kcat (D-serine) decreased compared to wild-type, no reaction towards beta-chloro-D-alanine |
729705 |
4.3.1.18 | more |
reduction of the aldimine linkage tethering PLP to recombinant, tagged D-serine dehydratase by treatment with NaBH4 so as to yield an inactive form of the holoenzyme, DsdR, which is further treated with a protease in order to remove the amino-terminal purification tag. Fourier Transform infrared spectroscopic analysis reveals that both the reduced form DsdR and the reduced/detagged form DsdRD maintain the overall secondary structure of wild-type, but feature a significantly increased thermal stability. The observed Tm values for DsdR and for DsdRD shift to 71.5°C and 73.3°C, respectively, resulting in nearly 11° and 13° higher than the one measured for wild-type. Though catalytically inert, DsdRD retains the ability to enantioselectively bind its natural substrate |
714380 |
4.3.1.18 | T166A |
in apo-wild-type enzyme and in holo-mutant enzyme T166A structures, which are in the open conformation, Thr166 is about 8-9 A away from a modelled pyridoxal 5'-phosphate D-Ser-external aldimine complex. This distance is too large to function as a proton abstracting residue. Thr166 is important for the proton abstraction step of catalysis |
747007 |
4.3.1.18 | Y203A |
Km increased compared to wild-type, kcat decreased compared to wild-type. kcat ratio: 14% (wild-type 100%) |
729953 |
4.3.1.18 | Y203D |
Km increased compared to wild-type, kcat decreased compared to wild-type. kcat ratio: 0.57% (wild-type 100%) |
729953 |