Nucleotide sequence of a cDNA coding for the mitochondrial precursor protein of cytochrome c oxidase subunit IV from the slime mold Dictyostelium discoideum.

Subunit-specific polyclonal antibodies were used to isolate cDNA clones encoding subunit IV of Dictyostelium discoideum cytochrome c oxidase. DNA sequence analysis reveals an open reading frame of 149 amino acids. As shown by sequencing of the protein N-terminus, the subunit is synthesized with a 24 residue cleavable presequence which leads to a mature polypeptide of 14305 Da. The slime mold subunit exhibits a low but significant degree of similarity with subunit Va of human and subunit VI of yeast cytochrome c oxidase.