MauG |
the diheme enzyme MauG catalyses a six-electron oxidation required for post-translational modification of preMADH (precursor of methylamine dehydrogenase) to complete the biosynthesis of its tryptophan tryptophylquinone, TTQ, cofactor. mutation of Trp93 of MauG to tyrosine causes loss of bound Ca2+ and alters the kinetic mechanism of tryptophan tryptophylquinone cofactor biosynthesis, overview. Whereas Ca2+-depleted wild-type MauG is inactive, W93Y MauG exhibits TTQ biosynthesis activity, although with much lower rate and highly unusual kinetic behaviour. The steady-state reaction exhibits a long lag phase, the duration of which is dependent on the concentration of preMADH, kinetic modeling. Analysis of th structures of Trp93 and Ca2+ site in MauG |
Paracoccus denitrificans |
|