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.
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.