PDBsum entry 4l3h

Oxidoreductase

PDB id: 4l3h

Contents

Protein chains

354 a.a.

129 a.a.

376 a.a.

Ligands

HEC ×4

EDO ×4

MES ×2

PGE

Metals

_NA ×4

_CA ×2

Waters ×1489

PDB id:

4l3h

Name:

Oxidoreductase

Title:

Crystal structure of the e113q-maug/pre-methylamine dehydrogenase complex after treatment with hydrogen peroxide

Structure:

Methylamine utilization protein maug. Chain: a, b. Engineered: yes. Mutation: yes. Methylamine dehydrogenase light chain. Chain: c, e. Fragment: unp residues 58-188. Engineered: yes. Methylamine dehydrogenase heavy chain.

Source:

Paracoccus denitrificans. Organism_taxid: 318586. Strain: pd 1222. Gene: maug, pden_4736. Expressed in: paracoccus denitrificans. Expression_system_taxid: 1063. Gene: pden_4733. Expressed in: rhodobacter spheroides. Gene: pden_4730.

Resolution:

1.79Å R-factor: 0.156 R-free: 0.198

Authors:

E.T.Yukl,C.M.Wilmot

Key ref:

N.Abu Tarboush et al. (2013). Carboxyl group of Glu113 is required for stabilization of the diferrous and bis-Fe(IV) states of MauG. Biochemistry, 52, 6358-6367. PubMed id: 23952537 DOI: 10.1021/bi400905s

Date:

05-Jun-13 Release date: 04-Sep-13

Protein chains

Q51658  (MAUG_PARDP) -  Methylamine utilization protein MauG from Paracoccus denitrificans (strain Pd 1222)

Seq: 387 a.a.

Struc: 354 a.a.*

Protein chains

A1BBA0  (A1BBA0_PARDP) -  Methylamine dehydrogenase (amicyanin) from Paracoccus denitrificans (strain Pd 1222)

Seq: 188 a.a.

Struc: 129 a.a.*

Protein chains

A1BB97  (A1BB97_PARDP) -  Methylamine dehydrogenase heavy chain from Paracoccus denitrificans (strain Pd 1222)

Seq: 417 a.a.

Struc: 376 a.a.

* PDB and UniProt seqs differ at 2 residue positions (black crosses)

Enzyme reactions

• Enzyme class 1: Chains A, B: E.C.1.-.-.-
• Enzyme class 2: Chains C, D, E, F: E.C.1.4.9.1 - methylamine dehydrogenase (amicyanin).
• Reaction: 2 oxidized [amicyanin] + methylamine + H2O = 2 reduced [amicyanin] + formaldehyde + NH4⁺ + 2 H⁺

2 × oxidized [amicyanin] + methylamine + H2O = 2 × reduced [amicyanin] (Bound ligand (Het Group name = EDO) matches with 50.00% similarity) + formaldehyde + NH4(+) + 2 × H(+)

• Cofactor: Tryptophan tryptophylquinone

Note, where more than one E.C. class is given (as above), each may correspond to a different protein domain or, in the case of polyprotein precursors, to a different mature protein.

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

Added reference

DOI no: 10.1021/bi400905s

Biochemistry 52:6358-6367 (2013)

PubMed id: 23952537

Carboxyl group of Glu113 is required for stabilization of the diferrous and bis-Fe(IV) states of MauG.

N.Abu Tarboush, E.T.Yukl, S.Shin, M.Feng, C.M.Wilmot, V.L.Davidson.

ABSTRACT

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-Fe(IV) state of MauG, in which one heme is Fe(IV)═O and the other is Fe(IV) 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 Fe(II)/Fe(III) 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-Fe(IV) 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-Fe(IV) redox state.