Cloned (Comment) | Organism |
---|---|
gene ndmC, recombinant overexpression of His-tagged wild-type and mutant NdmC proteins, coexpression with NdmD and NdmE | Pseudomonas putida |
Protein Variants | Comment | Organism |
---|---|---|
H120A/D237A | site-directed mutagenesis, catalytically inactive mutant | Pseudomonas putida |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
7-methylxanthine + O2 + NADH + H+ | Pseudomonas putida | immediate degradation via the NdmCDE complex | xanthine + NAD+ + H2O + formaldehyde | - |
? | |
7-methylxanthine + O2 + NADH + H+ | Pseudomonas putida CBB5 | immediate degradation via the NdmCDE complex | xanthine + NAD+ + H2O + formaldehyde | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Pseudomonas putida | M1EY73 | - |
- |
Pseudomonas putida CBB5 | M1EY73 | - |
- |
Purification (Comment) | Organism |
---|---|
recombinant His-tagged wild-type and mutant NdmC proteins by nickel affinity chromatography and gel filtration | Pseudomonas putida |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
cell culture | soil bacterium Pseudomonas putida strain CBB5 can use caffeine (1,3,7-trimethylxanthine) as a sole carbon and nitrogen source | Pseudomonas putida | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
7-methylxanthine + O2 + NADH + H+ | immediate degradation via the NdmCDE complex | Pseudomonas putida | xanthine + NAD+ + H2O + formaldehyde | - |
? | |
7-methylxanthine + O2 + NADH + H+ | NdmC specifically detaches methyl groups from the N-7 position of methylxanthine derivatives | Pseudomonas putida | xanthine + NAD+ + H2O + formaldehyde | - |
? | |
7-methylxanthine + O2 + NADH + H+ | immediate degradation via the NdmCDE complex | Pseudomonas putida CBB5 | xanthine + NAD+ + H2O + formaldehyde | - |
? | |
7-methylxanthine + O2 + NADH + H+ | NdmC specifically detaches methyl groups from the N-7 position of methylxanthine derivatives | Pseudomonas putida CBB5 | xanthine + NAD+ + H2O + formaldehyde | - |
? |
Subunits | Comment | Organism |
---|---|---|
More | the enzyme occurs as a Rieske nonheme iron oxygenase (RO)-reductase complex, the NdmCDE heterotrimer. NdmCDE domain architecture analysis, NdmC contains the ligand-binding domain, and the remaining Rieske domain must be nonfunctional because the metal coordinating residues are not conserved. Instead, a potentially functional, unique Rieske domain is located at the N-terminus of NdmD. In addition to the N-terminal Rieske domain, NdmD is composed of a flavin mononucleotide (FMN)-binding domain, an NADH-binding domain, and a C-terminal plant-type ferredoxin domain. NdmE has no discernable function, but exhibits high structural similarity to many glutathione-S-transferases. NdmE might facilitate complex formation by structural alignment | Pseudomonas putida |
Synonyms | Comment | Organism |
---|---|---|
bacterial N-demethylase | - |
Pseudomonas putida |
NdmC | - |
Pseudomonas putida |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
30 | - |
assay at | Pseudomonas putida |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.5 | - |
assay at | Pseudomonas putida |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
NADH | - |
Pseudomonas putida |
General Information | Comment | Organism |
---|---|---|
metabolism | Rieske nonheme iron oxygenases (ROs) catalyze the initial oxygenation reaction of aromatic compounds by enantio- and regiospecific reactions. The type of RO in Pseudomonas putida strain CBB5, consists of NdmA, NdmB, and NdmC, which specifically detach methyl groups from the N-1, N-3, and N-7 positions of methylxanthine derivatives, respectively. A single formaldehyde is produced whenever one N-linked methyl group is detached, indicating that NdmA, NdmB, and NdmC are monooxygenases.The N-demethylation of caffeine to xanthine occurs via three steps; NdmA and NdmB catalyze the initial two steps of N-demethylation, and the intermediate product, 7-methylxanthine, is further catalyzed to xanthine by an unusual RO-reductase complex, the NdmCDE heterotrimer. Heterohexamerization of NdmA and NdmB under physiological conditions. NdmD is the RO reductase that forms a stable ternary complex with NdmC and NdmE (NdmCDE). Since NdmC detaches the N-7 methyl group from methylxanthine derivatives, the NdmCDE complex is responsible for the last N-demethylation step of caffeine to xanthine. But NdmD is also needed by both NdmA and NdmB for electron transport from NADH to the oxygen activation site. Therefore, it is expected that transient interaction would exist between them. Electron transfer pathway from the ferredoxin domain of NdmD to caffeine in the catalytic site of NdmA. Enzyme complex structure analysis structure-function analysis, overview | Pseudomonas putida |
physiological function | some bacteria, such as Pseudomonas putida strain CBB5, utilize caffeine as a sole carbon and nitrogen source by degrading it through sequential N-demethylation catalyzed by five enzymes: NdmA, NdmB, NdmC, NdmD, and NdmE. Enzyme NdmC specifically detaches methyl groups from the N-7 position of methylxanthine derivatives, NdmC is a monooxygenase | Pseudomonas putida |