CcmF(C) involved in cytochrome c maturation is present in a large sized complex in wheat mitochondria.
In land plant mitochondria, c-type cytochromes are assembled via a mechanism similar to that found in Gram-negative bacteria and different from that used by mitochondria from other eukaryotes. The wheat mitochondrial genome encodes CCM (for cytochrome c maturation) proteins, among them CcmF(C), a protein similar to the C-terminal part of the bacterial CcmF. The gene is transcribed into a 1.7 kb transcript at steady state. However, the 3' termini of the transcript were found to occur upstream of the deduced gene termination codon. This discrepancy was solved by RNA editing that introduces a novel termination codon, thus shortening the reading frame by 27 codons. The processed transcript is translated into a protein integrated in the mitochondrial inner membrane. We also show that the protein is part of a large (700 kDa) protein complex, that possibly represents a cytochrome c assembly complex.
Giegé
Philippe
P
Institut de Biologie Moléculaire des Plantes-Centre National de la Recherche Scientifique, 12 rue du général Zimmer, 67084 Strasbourg, France. philippe.giege@ibmp-ulp.u-strasbg.fr
Rayapuram
Naganand
N
Meyer
Etienne H
EH
Grienenberger
Jean Michel
JM
Bonnard
Géraldine
G
D000595:Amino Acid Sequence; D003062:Codon; D018388:Codon, Terminator; D017124:Conserved Sequence; D003574:Cytochrome c Group / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D017343:Genes, Plant; D018745:Genome, Plant; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008928:Mitochondria / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016366:Open Reading Frames; D017393:RNA Editing; D015183:Restriction Mapping; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic; D014908:Triticum / Q000235:genetics* / Q000378:metabolism
D003062:Codon; D018388:Codon, Terminator; D003574:Cytochrome c Group; D008565:Membrane Proteins