Cytochrome domain of cellobiose dehydrogenase. CDH-cyt is the cytochrome domain, at the N-terminus, of cellobiose dehydrogenase. CDH-cyt folds as a beta sandwich with the topology of the antibody Fab V(H) domain and binds iron. The haem iron is ligated by Met83 and His181 in UniProtKB:Q01738.
Heme-binding cytochrome domain of fungal cellobiose dehydrogenases. Cellobiose dehydrogenase (CellobioseDH or CDH) is an extracellular fungal oxidoreductase that degrades both lignin and cellulose. Specifically, CDHs oxidize cellobiose, cellodextrins, and lactose to corresponding lactones, utilizing a variety of electron acceptors. Class-II CDHs are monomeric hemoflavoenzymes that are comprised of a b-type cytochrome domain linked to a large flavodehydrogenase domain. The cytochrome domain of CDH and related enzymes, which this model describes, folds as a beta sandwich and complexes a heme molecule. It is found at the N-terminus of this family of enzymes, and belongs to the DOMON domain superfamily, a ligand-interacting motif found in all three kingdoms of life.
DOMON-like domain of copper-dependent monooxygenases and related proteins. This diverse family characterizes DOMON domains found in dopamine beta-hydroxylase (DBH), monooxygenase X (MOX), and various other proteins, some of which contain DOMON domains exclusively; the family is not restricted to eukaryotes. DBH is a membrane-bound enzyme that converts dopamine to L-norepinephrine, and plays a central role in the metabolism of catecholamine neurotransmitters. DOMON domains were initially thought to confer protein-protein interactions. They were subsequently found as a heme-binding motif in cellobiose dehydrogenase, an extracellular fungal oxidoreductase that degrades both lignin and cellulose, and in ethylbenzene dehydrogenase, an enzyme that aids in the anaerobic degradation of hydrocarbons. The domain interacts with sugars in the type 9 carbohydrate binding modules (CBM9), which are present in a variety of glycosyl hydrolases, and it can also be found at the N-terminus of sensor histidine kinases.