Topology and function of CcmD in cytochrome c maturation.
The system I cytochrome c biogenesis pathway requires CcmD, a small polypeptide of 69 residues in Escherichia coli. Here it is shown that CcmD is a component of the CcmABC ATP-binding cassette transporter complex. CcmD is not necessary for the CcmC-dependent transfer of heme to CcmE in the periplasm or for interaction of CcmE with CcmABC. CcmD is absolutely required for the release of holo-CcmE from the CcmABCD complex. Evidence is presented that the topology of CcmD in the cytoplasmic membrane is the N terminus outside and the C terminus inside with one transmembrane domain.
Richard-Fogal
Cynthia L
CL
Department of Biology, Washington University, Campus Box 1137, 1 Brookings Drive, St. Louis, MO 63130, USA.
Frawley
Elaine R
ER
Kranz
Robert G
RG
D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D001692:Biological Transport; D002462:Cell Membrane; D045304:Cytochromes c / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D005798:Genes, Bacterial; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; C116246:CcmC protein, bacteria; C415989:CcmD protein, E coli; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D045304:Cytochromes c