TABLE 1.
Crystallographic statistics
Values in parentheses are for the highest resolution shell.
| Native | NaI derivative | |
|---|---|---|
| Data collection | ||
| Space group | R3 | R3 |
| Cell dimensions | ||
| a, b, c (Å) | 122.09, 122.09, 208.69 | 122.45, 122.45, 207.88 |
| α, β, γ (deg.) | 90, 90, 120 | 90, 90, 120 |
| Wavelength (Å) | 0.97856 | 1.5498 |
| Resolution range (Å) | 20.0–2.3 (2.4–2.3) | 20.0–3.2 (3.3–3.2) |
| Unique reflections | 49760 | 37630 |
| Completeness (%) | 96.6 (91.5) | 99.3 (96.7) |
| I/σ(I) | 11.2 (2.4) | 9.9 (2.3) |
| Redundancy | 3.3 | 4.5 |
| Rr.i.ma (%) | 8.0 (41.5) | 14.8 (52.6) |
| SIRAS phasing | ||
| Resolution range (Å) | 20.0–3.2 | |
| Numbers of heavy ions | 3 | |
| Ranomalous (%) | 0.09 | |
| Risomorphous (%) | 0.157 | |
| Figure of merit | 0.39 | |
| Refinement | ||
| Resolution range (Å) | 50–2.36 (2.51–2.36) | |
| Rworkb (%) | 24.5 (42.0) | |
| Rfreec (%) | 27.3 (43.4) | |
| Average B-values | ||
| 7456 protein atoms (Å2) | 65.4 | |
| 369 water molecules (Å2) | 58.9 | |
| 6 Ca2+ ions (Å2) | 58.2 | |
| r.m.s. deviation bonds (Å) | 0.009 | |
| r.m.s. deviation angles (degrees) | 1.2 | |
| Ramachandran (%) (favored, allowed, generously allowed, disallowed)d | 83.8, 15.4, 0.7, 0 | |
aRr.i.m refers to redundancy-independent merging R factor (43).
b Rwork = Σ|Fobs − Fcalc|/ΣFobs, where Fobs and Fcalc are the observed and the calculated structure factors, respectively.
c Rfree is calculated using 5% of reflections sequestered before refinement.