ENZYME

ENZYME entry: EC 1.1.5.5

Accepted Name

Alcohol dehydrogenase (quinone).

Alternative Name(s)

PQQ alcohol dehydrogenase.

PQQ-dependent ADH.

PQQ-dependent alcohol dehydrogenase.

Pyrroloquinoline quinone-dependent alcohol dehydrogenase.

Quinoprotein ADH.

Quinoprotein alcohol dehydrogenase.

Type III ADH.

Reaction catalysed

Ethanol + ubiquinone <=> acetaldehyde + ubiquinol

Cofactor(s)

Pyrroloquinoline quinone.

Comment(s)

Only described in acetic acid bacteria where it is involved in acetic acid production.
Associated with membrane.
Electron acceptor is membrane ubiquinone.
A model structure suggests that, like all other quinoprotein alcohol dehydrogenases, the catalytic subunit has an 8-bladed 'propeller' structure, a calcium ion bound to the PQQ in the active site and an unusual disulfide ring structure in close proximity to the PQQ; the catalytic subunit also has a heme c in the C-terminal domain.
The enzyme has two additional subunits, one of which contains three molecules of heme c.
It does not require amines for activation.
It has a restricted substrate specificity, oxidizing a few primary alcohols (C2 to C6), but not methanol, secondary alcohols and some aldehydes.
It is assayed with phenazine methosulfate or with ferricyanide.

Cross-references

BRENDA

EC2PDB

ExplorEnz

PRIAM enzyme-specific profiles

KEGG Ligand Database for Enzyme Nomenclature

IUBMB Enzyme Nomenclature