![]() | Class f: Membrane and cell surface proteins and peptides [56835] (50 folds) |
![]() | Fold f.21: Heme-binding four-helical bundle [81344] (3 superfamilies) core: four transmembrane helices, up-and-down bundle, binds one or two heme groups in between the helices |
![]() | f.21.2.1: Fumarate reductase respiratory complex cytochrome b subunit, FrdC [56910] (1 protein) duplication: consists of two structural repeats; the heme-binding sites are related by pseudo two fold symmetry |
![]() | f.21.2.2: Succinate dehydrogenase/Fumarate reductase transmembrane subunits (SdhC/FrdC and SdhD/FrdD) [81373] (4 proteins) consists of two homologous non-identical subunits that form a heterodimer; may or may not contain heme groups |
Timeline for Superfamily f.21.2: Fumarate reductase respiratory complex transmembrane subunits: