Protein Variants | Comment | Organism |
---|---|---|
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 | Homo sapiens |
W697Y | 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. W697Y shows a 3.4fold increase in kcat and a 6.7fold increase in catalytic efficiency for NADPH. The mutant displays modest decreases in cytochrome c3+ reduction, a 3.5fold decrease in the rate of FAD reduction, accumulation of a FADH2-NADP+ charge-transfer complex, and dramatically suppressed rates of interflavin electron transfer | Homo sapiens |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
2',5'-ADP | competitive inhibition | Homo sapiens | |
NADP+ | competitive inhibition in the reaction with NADPH and cytochrome c3+ as substrates, overview | Homo sapiens |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | steady-state kinetics analysis of wild-type and mutant enzymes with cytochrome c3+ and NADPH as substrates, overview | Homo sapiens |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
2 [methionine synthase]-methylcob(I)alamin + 2 S-adenosylhomocysteine + NADP+ | Homo sapiens | - |
2 [methionine synthase]-cob(II)alamin + NADPH + H+ + 2 S-adenosyl-L-methionine | - |
? |
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 | mechanism for the NADPH-catalyzed reduction of diflavin oxidoreductases, overview | Homo sapiens |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
2 [methionine synthase]-methylcob(I)alamin + 2 S-adenosylhomocysteine + NADP+ | - |
Homo sapiens | 2 [methionine synthase]-cob(II)alamin + NADPH + H+ + 2 S-adenosyl-L-methionine | - |
? | |
2 [methionine synthase]-methylcob(I)alamin + 2 S-adenosylhomocysteine + NADP+ | the enzyme transfers reducing equivalents from NADPH via an FAD and FMN cofactor to a redox partner protein. hydride transfer from NADPH to FAD requires displacement of a conserved tryptophan that lies coplanar to the FAD isoalloxazine ring | Homo sapiens | 2 [methionine synthase]-cob(II)alamin + NADPH + H+ + 2 S-adenosyl-L-methionine | - |
? | |
additional information | the enzyme catalyzes the reduction of cytochrome c3+ with NADPH and NADH | Homo sapiens | ? | - |
? |
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 |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.5 | - |
assay at | Homo sapiens |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
FAD | - |
Homo sapiens | |
FMN | - |
Homo sapiens | |
NADP+ | - |
Homo sapiens |
Ki Value [mM] | Ki Value maximum [mM] | Inhibitor | Comment | Organism | Structure |
---|---|---|---|---|---|
0.0001 | - |
2',5'-ADP | pH 7.5, 25°C, mutant W697F, with cytochrome c3+ | Homo sapiens | |
0.0007 | - |
2',5'-ADP | pH 7.5, 25°C, mutant W697Y, with cytochrome c3+ | Homo sapiens | |
0.0014 | - |
2',5'-ADP | pH 7.5, 25°C, wild-type enzyme | Homo sapiens | |
0.003 | - |
NADP+ | pH 7.5, 25°C, mutant W697F, with cytochrome c3+ | Homo sapiens | |
0.0042 | - |
NADP+ | pH 7.5, 25°C, mutant W697Y, with cytochrome c3+ | Homo sapiens | |
0.037 | - |
NADP+ | pH 7.5, 25°C, wild-type enzyme | Homo sapiens |