Lineage for Fold f.21: Heme-binding four-helical bundle

  1. Root: SCOP 1.75
  2. 886031Class f: Membrane and cell surface proteins and peptides [56835] (58 folds)
  3. 887002Fold 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


  1. 887003f.21.1: Transmembrane di-heme cytochromes [81342] (2 families) (S)
    Three of the four heme-ligands are conserved between the two families; both heme groups bind similarly but not identically
  2. 887060f.21.2: Fumarate reductase respiratory complex transmembrane subunits [81343] (2 families) (S)
    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
  3. 887111f.21.3: Respiratory nitrate reductase 1 gamma chain [103501] (1 family) (S)
    possible link between the two other superfamilies: this subunit corresponds to the gamma subunit of a functionally related Formate dehydrogenase N complex but is structurally closer to the Fumarate reductase subunit FrdC

More info for Fold f.21: Heme-binding four-helical bundle

Timeline for Fold f.21: Heme-binding four-helical bundle: