Literature summary extracted from
Shin, S.; Davidson, V.L.
MauG, a diheme enzyme that catalyzes tryptophan tryptophylquinone biosynthesis by remote catalysis (2014), Arch. Biochem. Biophys., 544, 112-118 .
Activating Compound
EC Number |
Activating Compound |
Comment |
Organism |
Structure |
---|
1.4.9.1 |
amicyanin |
- |
Paracoccus denitrificans |
|
1.4.9.1 |
MauG |
pre-enzyme MADH and its activator MauG perform a distinct form of enzyme catalysis that requires multi-step hole hopping-mediated long range electron transfer, mechanism, overview. The distance between the modified residues of preMADH and the nearest heme iron of MauG is 19 A, which is still a relatively long distance for biological electron transfer. MauG behaves more like a b-type heme enzyme than a c-type heme enzyme. Residue Trp93 and the bound Ca2+ are also components of the diheme cofactor. Ca2+ is positioned in the vicinity of the two hemes and is connected to each heme via H-bonding networks that include bound waters. Ca2+-depleted MauG shows no TTQ biosynthesis activity and exhibits altered absorbance, EPR and resonance Raman spectral properties. Re-addition of Ca2+ fully restores activity and the native spectral properties. Residue Pro107 is critical in maintaining the properstructure of the distal heme pocket of the high-spin heme of MauG to allow oxygen to bind. Trp199 of MauG, which resides at the MauG-preMADH interface, is positioned midway between the residues on preMADH that are modified and the nearest heme. Kinetic mechanism of MauG-dependent TTQ biosynthesis, overview |
Paracoccus denitrificans |
|
1.4.9.1 |
additional information |
the gene which encodes MauG is located in the methylamine utilization (mau) gene cluster of several gram negative bacteria. The mau cluster contains the two structural genes for MADH as well as accessory proteins that are required for MADH biogenesis |
Paracoccus denitrificans |
|
Cloned(Commentary)
EC Number |
Cloned (Comment) |
Organism |
---|
1.4.9.1 |
MADH is a heterotetramer consisting of two alpha subunits and two beta subunits which are encoded by mauB and mauA, respectively |
Paracoccus denitrificans |
Natural Substrates/ Products (Substrates)
EC Number |
Natural Substrates |
Organism |
Comment (Nat. Sub.) |
Natural Products |
Comment (Nat. Pro.) |
Rev. |
Reac. |
---|
1.4.9.1 |
methylamine + H2O + 2 amicyanin |
Paracoccus denitrificans |
- |
formaldehyde + NH3 + 2 reduced amicyanin |
- |
? |
|
Organism
EC Number |
Organism |
UniProt |
Comment |
Textmining |
---|
1.4.9.1 |
Paracoccus denitrificans |
P22619 AND P29894 |
alpha and beta subunits encoded by genes mauA and mauB |
- |
Substrates and Products (Substrate)
EC Number |
Substrates |
Comment Substrates |
Organism |
Products |
Comment (Products) |
Rev. |
Reac. |
---|
1.4.9.1 |
methylamine + H2O + 2 amicyanin |
- |
Paracoccus denitrificans |
formaldehyde + NH3 + 2 reduced amicyanin |
- |
? |
|
Subunits
EC Number |
Subunits |
Comment |
Organism |
---|
1.4.9.1 |
heterotetramer |
alpha2beta2 |
Paracoccus denitrificans |
1.4.9.1 |
More |
MADH is a heterotetramer consisting of two alpha subunits and two beta subunits which are encoded by mauB and mauA, respectively |
Paracoccus denitrificans |
Cofactor
EC Number |
Cofactor |
Comment |
Organism |
Structure |
---|
1.4.9.1 |
tryptophan tryptophylquinone |
TTQ, the catalytic cofactor of enzyme MADH. It is not an exogenous cofactor but is instead derived from posttranslational modifications of the beta subunits of MADH as evidenced from the crystal structure of MADH. Kinetic mechanism of MauG-dependent TTQ biosynthesis, overview |
Paracoccus denitrificans |
|
General Information
EC Number |
General Information |
Comment |
Organism |
---|
1.4.9.1 |
physiological function |
MADH catalyzes the oxidative deamination of methylamine to formaldehyde and ammonia, a reaction which allows the host bacterium to use methylamine as a sole source of carbon, nitrogen and energy. MADH donates the electrons which it extracts from methylamine to the mauC gene product, a type 1 copper protein named amicyanin, which in turn transfers electrons to cytochrome c-551i. The catalytic cofactor of MADH is tryptophan tryptophyquinone, TTQ |
Paracoccus denitrificans |