Table 3. Parameters from SAXS and comparison to theoretical values.

Sample	Rg (nm)	MW (kDa)	Dmax (nm)	Displaced volume (nm3)
CaM (SAXS)	2.05	21.3	6	29.5
CaM+CnA-CBD (SAXS)	1.85	19.6	5.5	29.9
CaM+CnA-CBD (crystal)	2.25	38.4	7.7	47.4
CaM+CnA-CBD (half) (crystal)	1.72	18.4	5.5	22.6
1WRZ (crystal structure of a collapsed complex)	1.70	20.7	5.4	23.8
1UP5 (crystal structure of unliganded CaM)	2.29	16.7	7.0	20.4

For the SAXS samples, the molecular weight was estimated by comparing the forward scattering to that of bovine serum albumin, and the displaced volume is that of the average ab initio model from DAMMIN. For the crystal structures, all the values have been calculated using CRYSOL.