A rapid and sensitive assay for quantifying the activity of both aerobic and anaerobic ribonucleotide reductases acting upon any or all substrates
Fig 5
Activity of StNrdD class III ribonucleotide reductase enzyme.
(A) Activity assay data for ATP, dATP, and no allosteric activity effector in the presence of GTP (substrate) and TTP (specificity effector). Error bars are shown for all replicates (3 replicates per data point) but are too small to visualize for some conditions. (B) Activities calculated from assay data in (A). Each bar represents average activity +/- standard error of the mean for three replicates. All conditions contained 0.10 μM StNrdD with 1.5 ± 0.10 glycyl radicals/dimer, 1 mM substrate GTP, 1 mM specificity effector TTP, 5 mM DTT, and 12.5 mM sodium formate; the ATP condition contained 3 mM allosteric activator ATP whereas the dATP condition contained 3 mM allosteric inhibitor dATP.