Cytochrome c synthetase has been solubilized from yeast mitochondria using Triton X-100 and fractionated with ammonium sulfate. Use of this partially purified enzyme has permitted us to isolate a quantity of iso-1-cytochrome c formed from 125I-labeled apocytochrome c and hemin in the presence of a NADPH-generating system. Visible absorption spectra (pH 8.0 or 5.0) including alpha, beta, and Sor...

1. A detailed study of cytochrome c oxidase activity with Keilin-Hartree particles and purified beef heart enzyme, at low ionic strength and low cytochrome c concentrations, showed biphasic kinetics with apparent Km1 = 5 x 10(-8) M, and apparent Km2 = 0.35 to 1.0 x 10(-6) M. Direct binding studies with purified oxidase, phospholipid-containing as well as phospholiptaining aid-depleted, demonstr...

The gene for iso-1-cytochrome c from Saccharomyces cerevisiae was recloned into a pSP65 vector containing an active bacteriophage SP promoter. The iso-1-cytochrome c gene was cloned as an 856-base pair XhoI-HindIII fragment. When the resulting plasmid was digested at the HindIII site 279 bases downstream from the termination codon of the gene and transcribed in vitro using SP6 RNA polymerase, f...

Genomic DNA of the yeast, Saccharomyces cerevisiae, can be conveniently and specifically altered by transforming spheroplasts or lithium acetate-treated cells directly with synthetic oligonucleotides. Altered forms of iso-1-cytochrome c were generated by transforming a cyc1 mutant with oligonucleotides and selecting for at least partially functional revertants; the oligonucleotides contained a ...