Figure 4.

APS reductase 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. APS reductase activity is expressed as nanomoles per minute per milligram of protein. A, APS reductase activity in wild-type (♦), sac1 (▪), and sac1-C11 (▴) strains. B, APS reductase activity in wild-type (♦) and sac2 (●) strains. C, APS reductase activity in wild-type (♦) and sac3 (▴) strains. Each value is the mean of at least three independent samples ± sd.