Mutagenesis of tryptophan199 suggests that hopping is required for MauG-dependent tryptophan tryptophylquinone biosynthesis
نویسندگان
چکیده
منابع مشابه
Mutagenesis of tryptophan199 suggests that hopping is required for MauG-dependent tryptophan tryptophylquinone biosynthesis.
The diheme enzyme MauG catalyzes the posttranslational modification of the precursor protein of methylamine dehydrogenase (preMADH) to complete biosynthesis of its protein-derived tryptophan tryptophylquinone (TTQ) cofactor. Catalysis proceeds through a high valent bis-Fe(IV) redox state and requires long-range electron transfer (ET), as the distance between the modified residues of preMADH and...
متن کاملDiradical intermediate within the context of tryptophan tryptophylquinone biosynthesis.
Despite the importance of tryptophan (Trp) radicals in biology, very few radicals have been trapped and characterized in a physiologically meaningful context. Here we demonstrate that the diheme enzyme MauG uses Trp radical chemistry to catalyze formation of a Trp-derived tryptophan tryptophylquinone cofactor on its substrate protein, premethylamine dehydrogenase. The unusual six-electron oxida...
متن کاملMutation of Trp(93) of MauG to tyrosine causes loss of bound Ca(2+) and alters the kinetic mechanism of tryptophan tryptophylquinone cofactor biosynthesis.
The dihaem enzyme MauG catalyses a six-electron oxidation required for post-translational modification of preMADH (precursor of methylamine dehydrogenase) to complete the biosynthesis of its TTQ (tryptophan tryptophylquinone) cofactor. Trp93 of MauG is positioned midway between its two haems, and in close proximity to a Ca2+ that is critical for MauG function. Mutation of Trp93 to tyrosine caus...
متن کاملRedox Properties of Tryptophan Tryptophylquinone Enzymes
The pH dependence of the redox potentials for the oxidized/reduced couples of methylamine dehydrogenase (MADH) and aromatic amine dehydrogenase (AADH) were determined. For each enzyme, a change of 230 mV/pH unit was observed, indicating that the two-electron transfer is linked to the transfer of a single proton. This result differs from what was obtained from redox studies of a tryptophan trypt...
متن کاملHeme-dependent Tryptophan Oxidation: Mechanistic Studies on Tryptophan 2,3-Dioxygenase and MauG
Hemoenzymes are prevalent in nature and participate in a wide range of biological activities. Frequently, high-valence iron intermediates are involved in the catalytic events of these enzymes, especially when the activation of peroxide or dioxygen is involved. Building on the fundamental framework of iron-oxygen chemistry, the mechanistic understandings of these enzymes and their reactive inter...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Proceedings of the National Academy of Sciences
سال: 2011
ISSN: 0027-8424,1091-6490
DOI: 10.1073/pnas.1109423108