TABLE 1.
Crystallographic statistics
Numbers in parentheses refer to statistics for the highest shell of data. Se-MAD, selenium multiwavelength anomalous diffraction; R.M.S.D., root mean square deviation; PDB, Protein Data Bank.
| Apo-Bc-TubZ (Se-MAD) | GDP-Bc-TubZ | GTPγS-Bc-TubZ | |||
|---|---|---|---|---|---|
| Data collection | |||||
| Beamline | NW12A (Photon Factory) | BL26B2 (SPring-8) | BL26B2 (Spring-8) | ||
| Space group | P21 | P21 | P21 | ||
| Unit cell dimensions (a, b, c; β) | 54.8, 66.0, 58.4 Å; 106.9° | 48.8, 76.0, 96.9 Å; 104.6° | 49.5, 76.4, 97.6 Å; 105.2° | ||
| Data range (Å) | 50–2.1 | 50–1.9 | 50–3.3 | ||
| Peak | Edge | High remote | |||
| Wavelength (Å) | 0.97921 | 0.97940 | 0.96417 | 1.0000 | 1.0000 |
| No. unique reflections | 45,587 | 45,607 | 45,817 | 52,862 | 10,758 |
| Completeness (%) | 99.7 (99.9) | 99.7 (99.9) | 99.8 (99.7) | 97.8 (96.9) | 99.8 (100.0) |
| Multiplicity | 3.9 (3.8) | 3.8 (3.8) | 3.8 (3.7) | 5.2 (5.0) | 7.0 (6.8) |
| I/σ(I) | 20.5 (5.5) | 19.9 (4.78) | 16.4 (2.59) | 23.3 (3.5) | 22.7 (4.5) |
| Rmergea | 0.049 (0.224) | 0.050 (0.278) | 0.062 (0.471) | 0.059 (0.441) | 0.082 (0.377) |
| Overall figure of merit | 0.53 (SOLVE), 0.91 (RESOLVE) | ||||
| Refinement | |||||
| Resolution range (Å) | 50–2.1 | 50–1.9 | 50–3.3 | ||
| No. reflections in working set | 39,985 | 45,912 | 9285 | ||
| Rcryst (Rfree)b | 0.199 (0.247) | 0.185 (0.237) | 0.206 (0.294) | ||
| R.M.S.D. bond length (Å) | 0.0089 | 0.0078 | 0.0030 | ||
| R.M.S.D. bond angle | 1.4° | 1.4° | 0.76° | ||
| Most favored area (%) | 94.5 | 97.0 | 88.7 | ||
| Additionally allowed area (%) | 3.5 | 2.8 | 10.1 | ||
| Generously allowed area (%) | 2.0 | 0 | 0 | ||
| Disallowed area (%) | 0 | 0.2 | 1.2 | ||
| PDB code | 4EI8 | 4EI7 | 4EI9 | ||
a Rmerge = Σ|Iobs − 〈I〉|/ΣIobs, where Iobs is the intensity measurement and 〈I〉 is the mean intensity for multiply recorded reflections (20).
b Rcryst and Rfree = ΣFobs| − |Fcalc‖/|Fobs| for reflections in the working and test sets, respectively. The Rfree value was calculated using a randomly selected 10% of the data set that was omitted through all stages of refinement.