Glucose-methanol-choline oxidoreductases are defined by the presence of the "Glucose-methanol-choline oxidoreductase (IPR01213)" InterPro signature.

The D. melanogaster genome contains 3 GMC members on the 3rd chromosome (Gld, ninaG and CG6142) and 12 other GMC members in a cluster on the X-chromosome (12F5-13). Although these 12 genes share sequence similarity with choline dehydrogenase and glucose dehydrogenase, their sequence similarity to these two enzymes is not significantly greater than to any other GMC oxidoreductases. This indicates that they are unlikely to encode either choline or glucose dehydrogenase. Moreover, choline dehydrogenase has not been reported/detected in Drosophila (FBrf0202218).