4l1q

Crystal Structure of the E113Q-MauG/pre-Methylamine Dehydrogenase Complex

spinqualitylabelsall models 4l1q, resolution 1.92Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4l1q is a 6 chain structure with sequence from Paracoccus denitrificans pd1222. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: CA, EDO, HEC, MES, NA NonStd Res: 0AF Related: 3l4m, 4l3g, 4l3h Gene: mauG, Pden_4736 (Paracoccus denitrificans PD1222), Pden_4733 (Paracoccus denitrificans PD1222), Pden_4730 (Paracoccus denitrificans PD1222) Activity: Methylamine dehydrogenase (amicyanin), with EC number 1.4.9.1 Resources: FirstGlance, OCA, RCSB, PDBsum Function [MAUG_PARDP] Involved in methylamine metabolism. Essential for the maturation of the beta subunit of MADH, presumably via a step in the biosynthesis of tryptophan tryptophylquinone (TTQ), the cofactor of MADH. Publication Abstract from PubMed The diheme enzyme MauG catalyzes a six-electron oxidation required for post-translational modification of a precursor of methylamine dehydrogenase (preMADH) to complete the biosynthesis of its protein-derived tryptophan tryptophylquinone (TTQ) cofactor. Crystallographic studies have implicated Glu113 in the formation of the bis-FeIV state of MauG, in which one heme is FeIV horizontal lineO and the other is FeIV with His-Tyr axial ligation. An E113Q mutation had no effect on the structure of MauG but significantly altered its redox properties. E113Q MauG could not be converted to the diferrous state by reduction with dithionite but was only reduced to a mixed valence FeII/FeIII state, which is never observed in wild-type (WT) MauG. Addition of H2O2 to E113Q MauG generated a high valence state that formed more slowly and was less stable than the bis-FeIV state of WT MauG. E113Q MauG exhibited no detectable TTQ biosynthesis activity in a steady-state assay with preMADH as the substrate. It did catalyze the steady-state oxidation of quinol MADH to the quinone, but 1000-fold less efficiently than WT MauG. Addition of H2O2 to a crystal of the E113Q MauG-preMADH complex resulted in partial synthesis of TTQ. Extended exposure of these crystals to H2O2 resulted in hydroxylation of Pro107 in the distal pocket of the high-spin heme. It is concluded that the loss of the carboxylic group of Glu113 disrupts the redox cooperativity between hemes that allows rapid formation of the diferrous state and alters the distribution of high-valence species that participate in charge-resonance stabilization of the bis-FeIV redox state. Carboxyl Group of Glu113 Is Required for Stabilization of the Diferrous and Bis-Fe States of MauG.,Abu Tarboush N, Yukl ET, Shin S, Feng M, Wilmot CM, Davidson VL Biochemistry. 2013 Aug 30. PMID:23952537 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Methylamine dehydrogenase

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