FIGURE 1.

S. cerevisiae CMC2 codes for a protein required for respiratory growth. A, sequence alignment of S. cerevisiae CMC1 and CMC2. Gray arrows indicate conserved cysteine residues. B, the respiratory competent wild-type strain W303-1A (WT), a strain carrying a null allele of cmc2 (Δcmc2 or Δ), and a Δ strain overexpressing either CMC1 or CMC2 were grown overnight in liquid YPD media. 10-Fold serial dilutions of the two strains were plated on solid YPD or YPEG medium and incubated at 30 °C. Pictures were taken after 3 days of incubation. C, KCN-sensitive endogenous cell respiration measured polarographically in the presence of galactose. The bars indicate the mean ± S.D. from at least three independent sets of measurements.