Fig. 5.

Reversible, NTP-dependent redox switching in yeast p58C. (Left) Cartoon depicts DNA- and NTP-bound yeast p58C cycling between [4Fe4S]³⁺ and [4Fe4S]²⁺ states. (Right) CV scans of WT yeast p58C (blue), p58C Y397F (green), and p58C Y397L (red) in the presence of 1.25 mM ATP. WT p58C displays a signal at 149 ± 14 mV vs. NHE. Reductive SWV of WT and mutant p58C. A small signal near −80 to −90 mV vs. NHE appears for Y397F and Y397L. All scans were performed anaerobically, on 57 μM [4Fe4S] p58C variant and 1.25 mM ATP in 20 mM Hepes, pH 7.2, 75 mM NaCl, 100-mV/s scan rate for CV, 15-Hz frequency, 25-mV amplitude, 60-mV/s scan rate for SWV. Potentials reported are mean ±SD of at least three trials. The increase in current at −0.3 V vs. NHE appears in the buffer scan and is p58C-independent.