EC Number   |
Protein Variants |
Reference |
|---|
   1.16.1.8 | A312H |
site-directed mutangenesis, mutation of the catalytic residue leads to the kinetic coupling of hydride and interflavin electron transfer, and eliminates the formation of the FAD hydroquinone intermediate, substitution of Ala312 for His in MSR weakens NADP(H) binding as the Km for NADPH and Ki for NADP+ increases 6 and 1.7fold, respectively. NADPH reduction of A312H resembles that of native cytochrome P450 reductase, in that it occurs in two discrete kinetic phases, without the transient formation of the E-FADH2-FMN intermediate |
741764 |
| 1.16.1.8 | A312Q |
site-directed mutangenesis, the catalytic site mutant shows a 2.5fold increased Km and a slightly decreased Ki for the coenzyme FAD |
741764 |
| 1.16.1.8 | A66G |
naturally occuring mutation, the MTRR polymorphism leads to a lower affinity for substrate methionine synthase compared to the wild-type enzyme |
716185 |
| 1.16.1.8 | I22M |
natural occuring polymorphism, no significant association with bone mineral density or serum osteocalcin level |
673482 |
| 1.16.1.8 | more |
common naturally occuring polymorphisms are MTRR 66A>G or MTRR 524C>T, which affect the enzyme activity. Effects of the MTRR genotype on human status with respect to vitmain B6, plasma folate, homocysteine, and plasma cobalamine levels, modeling, detailed overview |
745034 |
| 1.16.1.8 | more |
construction of mouse model with a gene trap in the methionine synthase reductase gene. Mutant animals have increased plasma homocyst(e)ine, decreased plasma methionine, and increased tissue methyltetrahydrofolate levels. Mice do not show decreases in the S-adenosylmethionine/S-adenosylhomocysteine ratio in most tissues |
676037 |
| 1.16.1.8 | more |
generation of truncation mutant S698DELTA, which shows increased activity with cytochrome c3+ as substrate compared to the wild-type enzyme |
726959 |
| 1.16.1.8 | S175L |
natural occuring polymorphism, no significant association with bone mineral density or serum osteocalcin level |
673482 |
| 1.16.1.8 | S698A |
site-directed mutagenesis, the mutant shows reduced activity with cytochrome c3+ as substrate compared to the wild-type enzyme, the S698A mutant displays a 6fold reduction in kcat/Km for NADPH |
726959 |
| 1.16.1.8 | W697F |
site-directed mutagenesis, the mutant shows enhanced catalysis, noted by increases in kcat and kcat/Km(NADPH) for steady-state cytochrome c3+ reduction and a 10fold increase in the rate constant associated with hydride transfer, W697F shows a 2.4fold increase in kcat and a 4.8fold increase in catalytic efficiency for NADPH. The mutant displays modest decreases in cytochrome c3+ reduction, a 30fold decrease in the rate of FAD reduction, accumulation of a FADH2-NADP+ charge-transfer complex, and dramatically suppressed rates of interflavin electron transfer |
727476 |
