3RLM

Structure of the W199F MauG/pre-Methylamine Dehydrogenase complex after treatment with hydrogen peroxide

Summary for 3RLM

• Entry DOI: 10.2210/pdb3rlm/pdb
• Related: 3L4M 3L4O 3RMZ 3RN0 3RN1
• Descriptor: Methylamine utilization protein MauG, Methylamine dehydrogenase light chain, Methylamine dehydrogenase heavy chain, ... (8 entities in total)
• Functional Keywords: oxidoreductase, electron transport
• Biological source: Paracoccus denitrificans; More
• Cellular location: Periplasm: Q51658
• Total number of polymer chains: 6
• Total formula weight: 199987.36

Authors

Yukl, E.T.,Wilmot, C.M. (deposition date: 2011-04-19, release date: 2011-10-05, Last modification date: 2024-11-06)

Primary citation

Tarboush, N.A.,Jensen, L.M.,Yukl, E.T.,Geng, J.,Liu, A.,Wilmot, C.M.,Davidson, V.L.
Mutagenesis of tryptophan199 suggests that hopping is required for MauG-dependent tryptophan tryptophylquinone biosynthesis.
Proc.Natl.Acad.Sci.USA, 108:16956-16961, 2011

PubMed Abstract: 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 the nearest heme iron of MauG is 19.4 Å. Trp199 of MauG resides at the MauG-preMADH interface, positioned midway between the residues that are modified and the nearest heme. W199F and W199K mutations did not affect the spectroscopic and redox properties of MauG, or its ability to stabilize the bis-Fe(IV) state. Crystal structures of complexes of W199F/K MauG with preMADH showed no significant perturbation of the MauG-preMADH structure or protein interface. However, neither MauG variant was able to synthesize TTQ from preMADH. In contrast, an ET reaction from diferrous MauG to quinone MADH, which does not require the bis-Fe(IV) intermediate, was minimally affected by the W199F/K mutations. W199F/K MauGs were able to oxidize quinol MADH to form TTQ, the putative final two-electron oxidation of the biosynthetic process, but with k(cat)/K(m) values approximately 10% that of wild-type MauG. The differential effects of the W199F/K mutations on these three different reactions are explained by a critical role for Trp199 in mediating multistep hopping from preMADH to bis-Fe(IV) MauG during the long-range ET that is required for TTQ biosynthesis.

PubMed: 21969534
DOI: 10.1073/pnas.1109423108

Experimental method

X-RAY DIFFRACTION (2.13 Å)