Protein Domain : Cytochrome c-type biogenesis protein CcmC IPR003557

Type	Family
Description	Within mitochondria and bacteria, a family of related proteins is involved in the assembly of periplasmic c-type cytochromes: these include CycK [], CcmF [, ], NrfE [] and CcbS []. These proteins may play a role in guidance of apocytochromes and haem groups for their covalent linkage by the cytochrome-c-haem lyase. Members of the family are probably integralmembrane proteins, with up to 16 predicted transmembrane (TM) helices. The gene products of the hel and ccl loci have been shown to be required specifically for the biogenesis of c-type cytochromes in the Gram-negativephotosynthetic bacterium Rhodobacter capsulatus [ ]. Genetic and molecularanalyses show that the hel locus contains at least 4 genes, helA, helB, helC and orf52. HelA is similar to the ABC transporters and helA, helB, and helC are proposed to encode an export complex []. It is believed that thehel-encoded proteins are required for the export of haem to the periplasm, where it is subsequently ligated to the c-type apocytochromes []. However,while CcmB and CcmC have the potential to interact with CcmA, the 3 gene products probably associating to form a complex with (CcmA)2-CcmB-CcmCstoichiometry, the substrate for the putative CcmABC-transporter is probably neither haem nor c-type apocytochromes []. Hydropathy analysis suggeststhe presence of 6 TM domains.
Short Name	Cyt_c_biogenesis_CcmC