Accepted name: alcohol dehydrogenase (cytochrome c)
Reaction: a primary alcohol + 2 ferricytochrome c = an aldehyde + 2 ferrocytochrome c + 2 H+
Other name(s): type I quinoprotein alcohol dehydrogenase; quinoprotein ethanol dehydrogenase
Systematic name: alcohol:cytochrome c oxidoreductase
Comments: A periplasmic PQQ-containing quinoprotein. Occurs in Pseudomonas and Rhodopseudomonas. The enzyme from Pseudomonas aeruginosa uses a specific inducible cytochrome c550 as electron acceptor. Acts on a wide range of primary and secondary alcohols, but not methanol. It has a homodimeric structure [contrasting with the heterotetrameric structure of EC, methanol dehydrogenase (cytochrome c)]. It is routinely assayed with phenazine methosulfate as electron acceptor. Activity is stimulated by ammonia or amines. Like all other quinoprotein alcohol dehydrogenases it 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.
1.  Rupp, M. and Gorisch, H. Purification, crystallisation and characterization of quinoprotein ethanol dehydrogenase from Pseudomonas aeruginosa. Biol. Chem. Hoppe-Seyler 369 (1988) 431–439. [PMID: 3144289]
2.  Toyama, H., Fujii, A., Matsushita, K., Shinagawa, E., Ameyama, M. and Adachi, O. Three distinct quinoprotein alcohol dehydrogenases are expressed when Pseudomonas putida is grown on different alcohols. J. Bacteriol. 177 (1995) 2442–2450. [PMID: 7730276]
3.  Schobert, M. and Gorisch, H. Cytochrome c550 is an essential component of the quinoprotein ethanol oxidation system in Pseudomonas aeruginosa: cloning and sequencing of the genes encoding cytochrome c550 and an adjacent acetaldehyde dehydrogenase. Microbiology 145 (1999) 471–481. [PMID: 10075429]
4.  Keitel, T., Diehl, A., Knaute, T., Stezowski, J.J., Hohne, W. and Gorisch, H. X-ray structure of the quinoprotein ethanol dehydrogenase from Pseudomonas aeruginosa: basis of substrate specificity. J. Mol. Biol. 297 (2000) 961–974. [PMID: 10736230]
5.  Kay, C.W., Mennenga, B., Gorisch, H. and Bittl, R. Characterisation of the PQQ cofactor radical in quinoprotein ethanol dehydrogenase of Pseudomonas aeruginosa by electron paramagnetic resonance spectroscopy. FEBS Lett. 564 (2004) 69–72. [PMID: 15094044]
6.  Mennenga, B., Kay, C.W. and Gorisch, H. Quinoprotein ethanol dehydrogenase from Pseudomonas aeruginosa: the unusual disulfide ring formed by adjacent cysteine residues is essential for efficient electron transfer to cytochrome c550. Arch. Microbiol. 191 (2009) 361–367. [PMID: 19224199]
[EC created 1972 as EC, modified 1982, part transferred 2010 to EC]