Reaction: ethanol + ubiquinone = acetaldehyde + ubiquinol
Other name(s): type III ADH; membrane associated quinohemoprotein alcohol dehydrogenase
Systematic name: alcohol:quinone oxidoreductase
Comments: 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, oxidising a few primary alcohols (C2 to C6), but not methanol, secondary alcohols and some aldehydes. It is assayed with phenazine methosulfate or with ferricyanide.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:
1. Gomez-Manzo, S., Contreras-Zentella, M., Gonzalez-Valdez, A., Sosa-Torres, M., Arreguin-Espinoza, R. and Escamilla-Marvan, E. The PQQ-alcohol dehydrogenase of Gluconacetobacter diazotrophicus. Int. J. Food Microbiol. 125 (2008) 71-78. [PMID: 18321602]
2. Shinagawa, E., Toyama, H., Matsushita, K., Tuitemwong, P., Theeragool, G. and Adachi, O. A novel type of formaldehyde-oxidizing enzyme from the membrane of Acetobacter sp. SKU 14. Biosci. Biotechnol. Biochem. 70 (2006) 850-857. [PMID: 16636451]
3. Chinnawirotpisan, P., Theeragool, G., Limtong, S., Toyama, H., Adachi, O.O. and Matsushita, K. Quinoprotein alcohol dehydrogenase is involved in catabolic acetate production, while NAD-dependent alcohol dehydrogenase in ethanol assimilation in Acetobacter pasteurianus SKU1108. J. Biosci. Bioeng. 96 (2003) 564-571. [PMID: 16233574]
4. Frebortova, J., Matsushita, K., Arata, H. and Adachi, O. Intramolecular electron transport in quinoprotein alcohol dehydrogenase of Acetobacter methanolicus: a redox-titration stud. Biochim. Biophys. Acta 1363 (1998) 24-34. [PMID: 9526036]
5. Matsushita, K., Kobayashi, Y., Mizuguchi, M., Toyama, H., Adachi, O., Sakamoto, K. and Miyoshi, H. A tightly bound quinone functions in the ubiquinone reaction sites of quinoprotein alcohol dehydrogenase of an acetic acid bacterium, Gluconobacter suboxydans. Biosci. Biotechnol. Biochem. 72 (2008) 2723-2731. [PMID: 18838797]
6. Matsushita, K., Yakushi, T., Toyama, H., Shinagawa, E. and Adachi, O. Function of multiple heme c moieties in intramolecular electron transport and ubiquinone reduction in the quinohemoprotein alcohol dehydrogenase-cytochrome c complex of Gluconobacter suboxydans. J. Biol. Chem. 271 (1996) 4850-4857. [PMID: 8617755]
7. Matsushita, K., Takaki, Y., Shinagawa, E., Ameyama, M. and Adachi, O. Ethanol oxidase respiratory chain of acetic acid bacteria. Reactivity with ubiquinone of pyrroloquinoline quinone-dependent alcohol dehydrogenases purified from Acetobacter aceti and Gluconobacter suboxydans. Biosci. Biotechnol. Biochem. 56 (1992) 304-310.
8. Matsushita, K., Toyama, H. and Adachi, O. Respiratory chains and bioenergetics of acetic acid bacteria. Adv. Microb. Physiol. 36 (1994) 247-301. [PMID: 7942316]
9. Cozier, G.E., Giles, I.G. and Anthony, C. The structure of the quinoprotein alcohol dehydrogenase of Acetobacter aceti modelled on that of methanol dehydrogenase from Methylobacterium extorquens. Biochem. J. 308 (1995) 375-379. [PMID: 7772016]