The first analysed archegoniate mitochondrial gene (COX3) exhibits extraordinary features.
The first mitochondrial-encoded gene of an archegoniate has been identified, cloned and sequenced. The cytochrome oxidase III gene (cox3) of the moss Physcomitrella patens consists of a 618 bp open reading frame with high homology (around 72%) to known cox3 sequences of higher plants. Nevertheless, it is a quarter shorter than these. The cox3 gene of P. patens contains no introns and reveals a G + C-content of 41.3%. The region containing the cox3 gene exists as a single copy in the mitochondrial genome as shown by restriction mapping. In the 5' flanking sequence a putative ribosome binding site and a putative secondary structure were found. Two main transcripts of 2.4 kb and 2.6 kb were detected indicating a complex mitochondrial transcription pattern possibly due to co-transcription. Additional open reading frames were found downstream from, as well as upstream of, the cox3 gene. In Western blots a polyclonal cox3 antibody from yeast detected one single band with an apparent molecular weight of 22 kDa.
Marienfeld
J R
JR
Institut für Allgemeine Botanik, Universität Hamburg, Federal Republic of Germany.
Reski
R
R
Abel
W O
WO
D000595:Amino Acid Sequence; D001483:Base Sequence; D015139:Blotting, Southern; D015153:Blotting, Western; D003001:Cloning, Molecular; D003062:Codon; D004272:DNA, Mitochondrial / Q000235:genetics*; D003576:Electron Transport Complex IV / Q000235:genetics; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010944:Plants / Q000201:enzymology / Q000235:genetics*; D012313:RNA / Q000235:genetics; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid
D003062:Codon; D004272:DNA, Mitochondrial; D012313:RNA; D003576:Electron Transport Complex IV