TABLE 1.
Crystallographic data and refinement statistics
| Data collection | Native (collected at 100 K) |
| Resolution (Å) | 33.02-2.48 (2.59-2.48) |
| Crystallographic cell - P1 | a = 63.6 Å, b = 71.4 Å, c = 100.2 Å, α = 98.5°, β = 90.6°, γ = 90.1° |
| Observations | 255,677 |
| Unique reflections | 61,295 |
| Completeness (%) | 98.6 (98.3) |
| Redundancy | 4.2 (3.6) |
| Rmerge (%) | 8.5 (44.8) |
| <I/σI> | 15.0 (2.3) |
| Wilson plot B factor (Å2) | 48.8 |
| Model refinement | |
| Reflections (total/free) | 61,224/3,144 |
| Rfactor (Rfree), (%) | 22.6 (27.8) |
| Atoms (total/protein) | 9,730/9,508 |
| Root mean square deviation from ideal | |
| Bonds (Å) | 0.010 |
| Angles (°) | 1.26 |
| <B> factors, all atoms (Å2) | 45.3 |
| Complex 1 | |
| Activin A (chain A/chain B) | 33.3/32.8 |
| FSTL3 (chain C/chain D) | 48.1/41.1 |
| Complex 2 | |
| Activin A (chain E/chain F) | 32.6/32.9 |
| ESTL3 (chain G/chain H) | 48.1/41.0 |
| Other molecules (number, <B> factor) | |
| Water | 214 (45.6) |
| Sulfate | 1 (80.0) |
| N-acetylglucosamine | 2 (74.1) |
| Ethylene glycol | 3 (65.4) |
| Ramachandran plot statistics (number) | |
| Most favored | 90.5% (963) |
| Additionally allowed | 8.6% (92) |
| Generously allowed | 0.5% (5) |
| Disallowed | 0.4% (4) (Asn38 in all activin A chains) |