Figure 4. Influences of mutants in purine metabolism on cysteine catabolism to H₂S.

A Extracellular release of cysteine-generated H₂S (left panel) and growth curves (right panel) from wt and mutants in purine biosynthesis pathway, with and without adenine supplementation. B Extracellular release of cysteine-generated H₂S (left panel) and growth curves (right panel) from wt and mutants in folate derived one-carbon metabolism. H₂S formation was measured at 663 nm using detection-dye; discolouration of the dye represents release of H₂S. Experiments were carried out in a microtiter plate. Error bars represent the standard deviation for quadruplicate experiments.