Cloned (Comment) | Organism |
---|---|
recombinant expression of wild-type and mutant enzymes in Escherichia coli strain Rosetta2(DE3)pLysS | Homo sapiens |
Protein Variants | Comment | Organism |
---|---|---|
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 | Homo sapiens |
A312Q | site-directed mutangenesis, the catalytic site mutant shows a 2.5fold increased Km and a slightly decreased Ki for the coenzyme FAD | Homo sapiens |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
NADP+ | - |
Homo sapiens |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | stopped-flow and steady-state kinetic analysis | Homo sapiens | |
0.0024 | - |
NADPH | pH 7.5, 25°C, recombinant wild-type enzyme | Homo sapiens | |
0.0062 | - |
NADPH | pH 7.5, 25°C, recombinant mutant A312Q | Homo sapiens | |
0.015 | - |
NADPH | pH 7.5, 25°C, recombinant mutant A312H | Homo sapiens |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
2 [methionine synthase]-cob(II)alamin + NADPH + H+ + 2 S-adenosyl-L-methionine | Homo sapiens | - |
2 [methionine synthase]-methylcob(I)alamin + 2 S-adenosylhomocysteine + NADP+ | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Homo sapiens | Q9UBK8 | - |
- |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
2 [methionine synthase]-methylcob(III)alamin + 2 S-adenosyl-L-homocysteine + NADP+ = 2 [methionine synthase]-cob(II)alamin + NADPH + H+ + 2 S-adenosyl-L-methionine | hydride transfer and interflavin electron transfer are two catalytic steps represented by two distinct kinetic phases leading to transient formation of the FAD hydroquinone | Homo sapiens |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
2 [methionine synthase]-cob(II)alamin + NADPH + H+ + 2 S-adenosyl-L-methionine | - |
Homo sapiens | 2 [methionine synthase]-methylcob(I)alamin + 2 S-adenosylhomocysteine + NADP+ | - |
? |
Synonyms | Comment | Organism |
---|---|---|
Methionine synthase reductase | - |
Homo sapiens |
MSR | - |
Homo sapiens |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
25 | - |
assay at | Homo sapiens |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
3.6 | - |
NADPH | pH 7.5, 25°C, recombinant mutant A312H | Homo sapiens | |
7.2 | - |
NADPH | pH 7.5, 25°C, recombinant wild-type enzyme | Homo sapiens | |
7.8 | - |
NADPH | pH 7.5, 25°C, recombinant mutant A312Q | Homo sapiens |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.5 | - |
assay at | Homo sapiens |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
FAD | the proximal FAD histidine residue accelerates proton-coupled electron transfer from FADH2 to the higher potential FMN | Homo sapiens | |
FMN | the proximal FAD histidine residue accelerates proton-coupled electron transfer from FADH2 to the higher potential FMN | Homo sapiens | |
additional information | mechanism of NADPH reduction of a diflavin enzyme, overview | Homo sapiens | |
NADPH | - |
Homo sapiens |
Ki Value [mM] | Ki Value maximum [mM] | Inhibitor | Comment | Organism | Structure |
---|---|---|---|---|---|
0.0291 | - |
NADP+ | pH 7.5, 25°C, recombinant mutant A312Q | Homo sapiens | |
0.0369 | - |
NADP+ | pH 7.5, 25°C, recombinant wild-type enzyme | Homo sapiens | |
0.0729 | - |
NADP+ | pH 7.5, 25°C, recombinant mutant A312H | Homo sapiens |