4FA9

Crystal Structure of WT MauG in Complex with Pre-Methylamine Dehydrogenase Aged 30 Days

Summary for 4FA9

• Entry DOI: 10.2210/pdb4fa9/pdb
• Related: 3L4M 4FA4 4FA5 4FAN 4FAV 4FB1
• Descriptor: Methylamine utilization protein MauG, Methylamine dehydrogenase light chain, Methylamine dehydrogenase heavy chain, ... (10 entities in total)
• Functional Keywords: tryptophan tryptophylquinon, oxidoreductase-electron transfer complex, oxidoreductase-electron transport complex, oxidoreductase/electron transport
• Biological source: Paracoccus denitrificans; More
• Cellular location: Periplasm: Q51658 P22619
• Total number of polymer chains: 6
• Total formula weight: 200140.34

Authors

Yukl, E.T.,Wilmot, C.M. (deposition date: 2012-05-21, release date: 2013-03-06, Last modification date: 2024-10-30)

Primary citation

Yukl, E.T.,Liu, F.,Krzystek, J.,Shin, S.,Jensen, L.M.,Davidson, V.L.,Wilmot, C.M.,Liu, A.
Diradical intermediate within the context of tryptophan tryptophylquinone biosynthesis.
Proc.Natl.Acad.Sci.USA, 110:4569-4573, 2013

PubMed Abstract: 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 oxidation that results in tryptophan tryptophylquinone formation occurs in three discrete two-electron catalytic steps. Here the exact order of these oxidation steps in the processive six-electron biosynthetic reaction is determined, and reaction intermediates are structurally characterized. The intermediates observed in crystal structures are also verified in solution using mass spectrometry. Furthermore, an unprecedented Trp-derived diradical species on premethylamine dehydrogenase, which is an intermediate in the first two-electron step, is characterized using high-frequency and -field electron paramagnetic resonance spectroscopy and UV-visible absorbance spectroscopy. This work defines a unique mechanism for radical-mediated catalysis of a protein substrate, and has broad implications in the areas of applied biocatalysis and understanding of oxidative protein modification during oxidative stress.

PubMed: 23487750
DOI: 10.1073/pnas.1215011110

Experimental method

X-RAY DIFFRACTION (2.09 Å)