PDBsum entry 4fb1

Oxidoreductase/electron transfer

PDB id: 4fb1

Contents

Protein chains

354 a.a.

125 a.a.

376 a.a.

Ligands

HEC ×4

MES ×2

Metals

_NA ×3

_CA ×2

Waters ×656

PDB id:

4fb1

Name:

Oxidoreductase/electron transfer

Title:

Crystal structure of wt maug in complex with pre-methylamine dehydrogenase aged 60 days

Structure:

Methylamine utilization protein maug. Chain: a, b. Fragment: unp residues 21-387. Engineered: yes. Methylamine dehydrogenase light chain. Chain: c, e. Fragment: unp residues 58-188. Synonym: madh, methylamine dehydrogenase (amicyanin). Engineered: yes.

Source:

Paracoccus denitrificans. Organism_taxid: 318586. Strain: pd 1222. Gene: maug, pden_4736. Expressed in: paracoccus denitrificans. Expression_system_taxid: 266. Organism_taxid: 266. Gene: maua. Expressed in: rhodobacter sphaeroides.

Resolution:

2.15Å R-factor: 0.165 R-free: 0.222

Authors:

E.T.Yukl,C.M.Wilmot

Key ref:

E.T.Yukl et al. (2013). Diradical intermediate within the context of tryptophan tryptophylquinone biosynthesis. Proc Natl Acad Sci U S A, 110, 4569-4573. PubMed id: 23487750 DOI: 10.1073/pnas.1215011110

Date:

22-May-12 Release date: 27-Mar-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

P22619  (DHML_PARDE) -  Methylamine dehydrogenase light chain from Paracoccus denitrificans

Seq: 188 a.a.

Struc: 125 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 1 residue position (black cross)

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⁺
• 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: 10.1073/pnas.1215011110

Proc Natl Acad Sci U S A 110:4569-4573 (2013)

PubMed id: 23487750

Diradical intermediate within the context of tryptophan tryptophylquinone biosynthesis.

E.T.Yukl, F.Liu, J.Krzystek, S.Shin, L.M.Jensen, V.L.Davidson, C.M.Wilmot, A.Liu.

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.