1PBY: Structure Of The Phenylhydrazine Adduct Of The Quinohemoprotein Amine Dehydrogenase From Paracoccus Denitrificans At 1.7 A Resolution

Citation:
Abstract
The 109 kDa quinohemoprotein amine dehydrogenase (QHNDH) from Paracoccus denitrificans contains a novel redox cofactor, cysteine tryptophylquinone (CTQ). This cofactor is derived from a pair of gene-encoded amino acids by post-translational modification and was previously identified and characterized within an 82-residue subunit by chemical methods and crystallographic analysis at 2.05 A resolution. It contains an orthoquinone moiety bound to the indole ring and catalyzes the oxidation of aliphatic and aromatic amines through formation of a Schiff-base intermediate involving one of the quinone O atoms. This paper reports the structural analysis of the complex of QHNDH with the enzyme inhibitor phenylhydrazine determined at 1.70 A resolution. The phenylhydrazone product is attached to the C6 position, identifying the O6 atom of CTQ as the site of Schiff-base formation as postulated by analogy to another amine-oxidizing enzyme, methylamine dehydrogenase. Furthermore, the inner N atom closest to the phenyl ring of phenylhydrazine forms a hydrogen bond to gammaAsp33 in the complex, lending support to the hypothesis that this residue serves as the active-site base for proton abstraction during catalysis.
PDB ID: 1PBYDownload
MMDB ID: 23772
PDB Deposition Date: 2003/5/15
Updated in MMDB: 2017/11
Experimental Method:
x-ray diffraction
Resolution: 1.7  Å
Source Organism:
Similar Structures:
Biological Unit for 1PBY: trimeric; determined by author and by software (PISA)
Molecular Components in 1PBY
Label Count Molecule
Proteins (3 molecules)
1
Quinohemoprotein Amine Dehydrogenase 60 KDA Subunit
Molecule annotation
1
Quinohemoprotein Amine Dehydrogenase 40 KDA Subunit
Molecule annotation
1
Quinohemoprotein Amine Dehydrogenase 9 KDA Subunit
Molecule annotation
Chemicals (6 molecules)
1
2
2
4
* Click molecule labels to explore molecular sequence information.

Citing MMDB
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