TABLE 2.
Sulfur sources in the growth mediuma | Atom % of 34S |
||
---|---|---|---|
Fe-S | Cys | Met | |
[32S]Cys + [34S]Na2Sb | 87 ± 4 | 8 ± 2 | 92 ± 3 |
[32S]Cystathionine + [34S]Na2Sc | 84 | 5 | 5 |
[32S]Cys + [32S]Hcy + [34S]Na2Sd | 90 | 9 | 7 |
a Cells were grown in media containing 1.5 mm [34S]sulfide, 3 mm l-cysteine, 5 mm l-cystathionine, and/or 3 mm l-homocysteine as indicated. The numbers represented the measured atom % of 34S in the derivatives of the indicated molecules. The 34S enrichment of Na2S used as the substrate was 92.6%. The natural abundance of 34S in the sulfur-containing amino acids was 4.2%.
b Values are the means of three independent experiments ± 1 S.D.
c Medium contained 1.5 mm coenzyme M as a reductant.
d Values are the means of two independent experiments.