AUC-SE data for YahA-EAL in the presence of 2 mm CaCl2. Protein and substrate concentrations are indicated. For each sample, data are shown for three speeds (9,700, 16,500, and 28,000 rpm). All six runs were fitted globally to a dynamic monomer-dimer self-association model with the monomer mass set to 31 kDa. The fit yielded a dimerization Kd of 0.5 μm (Table 3).