Fig. 4

Turnover rate of wildtype and Cox13Δ-CytcO as a function of added yeast cyt. c in the absence (a) and presence (b) of 5 mM ATP. The turnover rate is expressed as relative to the maximum rate achieved (in e^-/s) at 100 μM cyt. c in the absence of additions for both the wildtype and Cox13Δ-CytcO. For original data, see Additional file 1: Figure S7 and Additional file 2. Data points shown are averages and error bars are standard deviations (n=3). In a, the lines shown are fits to two hyperbolic functions with two K_ms as follows: Wildtype (black line): V¹: 40±10%, K_m¹: 1.3±0.6 μM, V²: 70±10%, K_m²: 20±10 μM. Cox13Δ-CytcO (red line) V¹: 43±7%, K_m¹: 0.2±0.1 μM V²: 74±7%, K_m²: 20±10 μM. In b, the lines are fits to a simple Michaelis-Menten equation (one K_m): for wildtype (black line) with V: 208±2%, K_m: 8.6±0.3 μM and for Cox13Δ-CytcO (red line): 236±3%, K_m: 5.8±0.3 μM. Experimental conditions: 25 mM KP_i pH 7.0, 0.035% DDM, 10 mM ascorbate, and 100 μM TMPD