Mitochondrial DNA of Chlamydomonas reinhardtii: the gene for apocytochrome b and the complete functional map of the 15.8 kb DNA.

We have sequenced the termini of the mitochondrial genome of Chlamydomonas reinhardtii and now present the DNA sequence of the gene for apocytochrome b. This gene is the thirteenth gene of the linear 15.8 kb DNA and appears to be the last one of the mt genome. The deduced protein sequence of 381 amino acid residues shows 56%, 48.6% and 48% identity with the apocytochrome b proteins of maize, Drosophila yakuba and mouse, respectively. RNA analysis reveals a transcript of about 1250 nucleotides. It is now possible to present the complete protein-coding capacity, the pattern of codon utilization for all eight protein genes, and the complete functional map of the mitochondrial 15.8 kb DNA of C. reinhardtii. One surprising feature is the absence of mitochondrial genes for ATPase and subunits II and III of cytochrome oxidase. No more than three tRNA genes appear to be present on the 15.8 kb mitochondrial DNA.