Structural Classification of Proteins

Superfamily: Fumarate reductase respiratory complex transmembrane subunits

: two distinct families: in one family the common fold is contained in a single-chain subunit, in the other it is formed by two chains

Lineage:

Root: scop
Class: Membrane and cell surface proteins and peptides [56835]
Does not include proteins in the immune system
Fold: Heme-binding four-helical bundle [81344]
core: four transmembrane helices, up-and-down bundle, binds one or two heme groups in between the helices
Superfamily: Fumarate reductase respiratory complex transmembrane subunits [81343]
two distinct families: in one family the common fold is contained in a single-chain subunit, in the other it is formed by two chains

Fumarate reductase respiratory complex cytochrome b subunit, FrdC [56910] (1)
duplication: consists of two structural repeats; the heme-binding sites are related by pseudo two fold symmetry
Succinate dehydrogenase/Fumarate reductase transmembrane subunits (SdhC/FrdC and SdhD/FrdD) [81373] (4)
consists of two homologous non-identical subunits that form a heterodimer; may or may not contain heme groups