Table 1.
SAXS Data and analysis.
| apo-EPAC1 | cAMP: EPAC1 | cAMP: EPAC1: Rap1b | |
|---|---|---|---|
| q-range (Å−1) | 0.010–0.30 | 0.012–0.30 | 0.012–0.30 |
| Concentration (mg/mL) | 0.5 | 2.7 | 1.0 |
| Time (h) | |||
| Sample | 6 | 2 | 2.5 |
| Buffer | 6 | 3 | 11.5 |
| Rg (Å) | 33.7 ± 0.5 | 53.2 ± 0.7 | 40.5 ± 0.6 |
| Dmax (Å) | 110 | 185 | 142 |
| MW (kDa) | 100 | 100 | 119 |
| MW(Io) (kDa) {N} | 104 {1.0} | 178 {1.8} | 98 {0.8} |
| MW(Porod) (kDa) {N} | 113 {1.1} | 240 {2.4} | 124 {1.0} |
| MW(Rambo) (kDa) {N} | 97.8 {1.0} | 218 {2.2} | 126 {1.1} |
| DAMMIF NSD (10) | 0.8 ± 3 | 1.0 ± 8 | 0.9 ± 1 |
| SASRES(Å) | 40 ± 3 | 14 ± 2 | 42 ± 3 |
| Rigid Body Fitting | |||
| HM Crysol fit (X2) | 1.3 | NA | NA |
| CORAL fit (X2) | 1.0 | 1.0 | 1.0 |
| CORAL Model Rg (Å) | 32.7 | 41.5 1 | 40.5 |
| EOM:(X2) | 1.0 | 1.1 | 0.7 |
| Rg [FWHM] 2 {Area} | |||
| Peak (closed) | 32.9 [0.8] 2 {86%} | 0 | 0 |
| Peak (extended) | 38.5 [0.9] 2 {13%} | 0 | 0 |
| Peak (ternary) | 0 | 0 | 40.7 [0.7] 2 {100%} |
| Peak (dimer) | 0 | 51 [3] 2 {100%} | 0 |
| SASDB-id | SASDCQ6 | SASDCR6 | SASDCS6 |
| Analysis | Software: | Analysis | Software: |
| Image Data-processing: | SAXSLAB (Rigaku) | Buffer Subtraction: | SAXNS-ES 3 [45] |
| Data-analysis: | PRIMUS [48] | Real Space P(r): | GNOM [48], BayesApp [49] |
| Ab initio Models: | DAMMIF [50] | Molecular Weight: | SAXSMOW [51] |
| Rigid Body Refinement: | CORAL [52], BUNCH | Ensemble Analysis: | EOM [53], MES [54] |
1 Dimer Rg is per monomer. The Coral dimer has a Rg of 54 Å. 2 The peak’s full-width at half-maximum (FWHM). 3 Appendix A.