A benzidine-HzOz staining procedure and genetic tests were used for the detection of cytochrome c-deficient mutants of the cyl, cy2, cy3, cy4, and cy6 loci. The chromosomal gene, CY1, was shown to encode the primary structure of iso-l-cytochrome c from bakers’ yeast. Sixteen cyl mutants were isolated after examining over 1 million colonies. These cyl mutants could be categorized as follows: (a)...

The four mutant genes, cyc2, cyc3, cyc8 and cyc9, that affect the levels of the two iso-cytochromes c in the yeast Saccharomyces cerevisiae have been characterized and mapped. Both cyc2 and cyc3 lower the amount of iso-1-cytochrome c and iso-2-cytochrome c; whereas, cyc8 and cyc9 increase the amount of iso-2-cytochrome c. The cyc2, cyc3, cyc8 and cyc9 genes are located, respectively, on chromos...

The complete amino acid sequence of chicken heart cytochrome c has been established. This primary structure is typically that of a “mammalian-type” cytochrome c showing the characteristic groupings of hydrophobic and basic residues, and, like the other cytochromes c from vertebrate species, has an acetylated amino-terminal residue. Chicken heart cytochrome c differs from the horse, beef, human,...

The complete amino acid sequence of chicken heart cytochrome c has been established. This primary structure is typically that of a “mammalian-type” cytochrome c showing the characteristic groupings of hydrophobic and basic residues, and, like the other cytochromes c from vertebrate species, has an acetylated amino-terminal residue. Chicken heart cytochrome c differs from the horse, beef, human,...

Cyclic voltammetry shows that yeast iso-1-cytochrome c (YCC), chemisorbed on a bare gold electrode via Cys102, exhibits fast, reversible interfacial electron transfer (k(0) = 1.8 x 10(3) s(-1)) and retains its native functionality. Vectorially immobilized YCC relays electrons to yeast cytochrome c peroxidase, and to both cytochrome cd(1) nitrite reductase (NIR) and nitric oxide reductase from P...

Asn-52 of rat cytochrome c and baker's yeast iso-1-cytochrome c was changed to isoleucine by site-directed mutagenesis and the mutated proteins expressed in and purified from cultures of transformed yeast. This mutation affected the affinity of the haem iron for the Met-80 sulphur in the ferric state and the reduction potential of the molecule. The yeast protein, in which the sulphur-iron bond ...