Figure 6.

O-Acetyl-Ser (thiol) lyase activity in wild-type and sac mutants. Cells were grown to mid-log phase in sulfate-replete medium, washed twice with sulfur-deficient medium, and were then incubated for 0, 1, 2, 4, 8, 12, or 24 h prior to harvesting. O-Acetyl-Ser (thiol) lyase activity is expressed as micromoles Cys produced per minute per milligram of protein. A, O-Acetyl-Ser (thiol) lyase activity in wild-type (♦), sac1 (▪), sac2 (●), and sac3 (♦) strains. B, O-Acetyl-Ser (thiol) lyase activity in wild-type (♦), sac1 (▪), and the complemented sac1 strain, sac1-C11 (▴). Each value is the mean of at least three independent samples ± sd. The standard deviations of these measurements were less than 4% of the values.