Activating Compound | Comment | Organism | Structure |
---|---|---|---|
MauG | 42 kDa activator enzyme of methylamine dehydrogenase, the MauG residue Gln103 is important for the redox properties and stability of MauG. The diheme enzyme MauG catalyzes a six electron oxidation that is required for the posttranslational modification of a precursor of methylamine dehydrogenase (preMADH) to complete the biosynthesis of its protein-derived cofactor, tryptophan tryptophylquinone (TTQ). The substrate for MauG that undergoes this posttranslational modification is a precursor protein of MADH (preMADH). It possesses a monohydroxylated residue betaTrp57. The reactions catalyzed by MauG occur in the following order: covalent cross-linking of monohydroxylated betaTrp57 to betaTrp108, incorporation of a second oxygen atom into the side chain of betaTrp57, and oxidation of the quinol species to the quinone. Catalysis requires long-range electron transfer because preMADH does not make direct contact with either heme of MauG. The electron transfer occurs via a hole-hopping mechanism in which Trp residues of MauG are reversibly oxidized. Steady-state kinetic parameters of the MauG-dependent biosynthesis of TTQ from preMADH, overview. Analysis of effects of the Q103 mutations on the visible absorption spectra of the diferric and diferrous redox states of MauG | Paracoccus denitrificans |
Crystallization (Comment) | Organism |
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purified preenzyme pre-MADH in complex with activator mutant Q103N MauG, X-ray diffraction structure determination and analysis | Paracoccus denitrificans |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Paracoccus denitrificans | P22619 AND P29894 | alpha and beta subunits encoded by genes mauA and mauB | - |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
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 | Paracoccus denitrificans |
General Information | Comment | Organism |
---|---|---|
physiological function | the diheme enzyme MauG catalyzes a six electron oxidation that is required for the posttranslational modification of a precursor of methylamine dehydrogenase (preMADH) to complete the biosynthesis of its protein-derived cofactor, tryptophan tryptophylquinone (TTQ). The substrate for MauG that undergoes this posttranslational modification is a precursor protein of MADH (preMADH). It possesses a monohydroxylated residue betaTrp57. The reactions catalyzed by MauG occur in the following order: covalent cross-linking of monohydroxylated betaTrp57 to betaTrp108, incorporation of a second oxygen atom into the side chain of betaTrp57, and oxidation of the quinol species to the quinone. Catalysis requires long-range electron transfer because preMADH does not make direct contact with either heme of MauG. The electron transfer occurs via a hole-hopping mechanism in which Trp residues of MauG are reversibly oxidized | Paracoccus denitrificans |