EC Number   |
Cofactor |
Reference |
|---|
   1.4.9.1 | tryptophan tryptophylquinone |
TTQ, methylamine dehydrogenase requires the cofactor tryptophan tryptophylquinone for activity. TTQ is a posttranslational modification that results from an 8-electron oxidation of two specific tryptophans in the MADH beta-subunit, betaTrp57 and betaTrp108. The final 6-electron oxidation is catalyzed by the unusual c-type di-heme enzyme, MauG. The di-ferric enzyme can react with H2O2, but atypically for c-type hemes the di-ferrous enzyme can react with O2 as well. In both cases, an unprecedented bis-Fe(IV) redox state is formed, composed of a ferryl heme (Fe(IV)=O) and the second heme as Fe(IV) stabilized by His-Tyr axial ligation. Bis-Fe(IV) MauG acts as a potent 2-electron oxidant. Catalysis is long-range and requires a hole hopping electron transfer mechanism. TTQ structure analysis, overview |
742338 |
| 1.4.9.1 | tryptophan tryptophylquinone |
TTQ, the catalytic cofactor of enzyme MADH. Activator enzyme MauG is involved in TTQ biosynthesis. Mutation of Trp93 of MauG to tyrosine causes loss of bound Ca2+ and alters the kinetic mechanism of tryptophan tryptophylquinone cofactor biosynthesis. The substrate for MauG-dependent TTQ biosynthesis is preMADH |
741849 |
| 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 |
741893 |
| 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 |
741759 |
| 1.4.9.1 | tryptophan tryptophylquinone |
TTQ, the quinone cofactor of the enzyme. QhpG is involved in the quinone cofactor formation |
741905 |
