The following FAD flavoproteins oxidoreductases have been found [1,2] to be evolutionary related. These enzymes, which are called 'GMC oxidoreductases', are listed below.

• Glucose oxidase (EC 1.1.3.4) (GOX) from Aspergillus niger. Reaction catalyzed: glucose + oxygen -> delta-gluconolactone + hydrogen peroxide.
• Methanol oxidase (EC 1.1.3.13) (MOX) from fungi. Reaction catalyzed: methanol + oxygen -> acetaldehyde + hydrogen peroxide.
• Choline dehydrogenase (EC 1.1.99.1) (CHD) from bacteria. Reaction catalyzed: choline + acceptor -> βine acetaldehyde + reduced acceptor.
• Glucose dehydrogenase (GLD) (EC 1.1.99.10) from Drosophila. Reaction catalyzed: glucose + acceptor -> delta-gluconolactone + reduced acceptor.
• L-sorbose 1-dehydrogenase (EC 1.1.99.32) (SDH) from Gluconobacter oxydans. Reaction catylzed: L-sorbose + acceptor = 1-dehydro-L-sorbose + reduced acceptor.
• Cholesterol oxidase (CHOD) (EC 1.1.3.6) from Brevibacterium sterolicum and Streptomyces strain SA-COO. Reaction catalyzed: cholesterol + oxygen -> cholest-4-en-3-one + hydrogen peroxide.
• AlkJ [3], an alcohol dehydrogenase from Pseudomonas oleovorans, which converts aliphatic medium-chain-length alcohols into aldehydes.
• Cellobiose dehydrogenase (CDH) (EC 1.1.98.18) from Phanerochaete chrysosporium.

This family also includes a lyase:

• (R)-mandelonitrile lyase (EC 4.1.2.10) (hydroxynitrile lyase) from plants [4], an enzyme involved in cyanogenis, the release of hydrogen cyanide from injured tissues.

These enzymes are proteins of size ranging from 556 (CHD) to 664 (MOX) amino acid residues which share a number of regions of sequence similarities. One of these regions, located in the N-terminal section, corresponds to the FAD ADP-binding domain. The function of the other conserved domains is not yet known; we have selected two of these domains as signature patterns. The first one is located in the N-terminal section of these enzymes, about 50 residues after the ADP-binding domain, while the second one is located in the central section.