Table 2.

Substrate-dependent oxygen-uptake activities of cell extracts of S. cerevisiae strains expressing Aadho or Scdho

Strain	Relevant genotype	Activity (nmol O2·mg protein−1·min−1)
		dihydrouracil	dihydrothymine
CEN.PK113-7D	URA1	< 2	< 2
IMK824	ura1∆	< 2	< 2
IME664	ura1∆ mcAadho	29.6 ± 6.5	46.1 ± 8.6
IME665	ura1∆ mcScdho	246 ± 13	340 ± 22

Activities were determined in cell extracts by monitoring oxygen upon addition of 1 mM dihydrouracil or 1 mM dihydrothymine. Experiments were performed with a Clark-type oxygen electrode, in a 4 mL reaction chamber kept at 30 °C and containing 0.1 M potassium phosphate buffer (pH 7.5) with 2 mM MgCl₂. Activities are presented as average and mean deviation of measurements on two independently prepared cell extracts for each strain