Table 1. Statistics for the crystallographic data collection and refinement of the Cx26 gap junction channel.
Values in parentheses are for the last shell.
| Crystal | Native I | Ta6Br14 derivative of native I | Native II | Ta6Br14 derivative of native II | SeMet derivative (edge) | SeMet derivative (remote) | Ta6Br14 derivative for MAD (peak) | Ta6Br14 derivative for MAD (edge) | Ta6Br14 derivative for MAD (remote) | S anomalous (high energy) | S anomalous (low energy) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Initial phase for multi-crystal averaging (phasing) | Native I (SIRAS) | Native II (SIR) | SeMet derivative (MAD) | Ta6Br14 derivative for MAD (MAD) | |||||||
| Data-collection statistics | |||||||||||
| No. of crystals | 10 | 2 | 2 | 4 | 1† | 1† | 2 | 1† | 1† | 1 | 2 |
| Space group | C2 | C2 | C2 | C2 | C2 | C2 | C2 | C2 | C2 | C2 | C2 |
| Unit-cell parameters | |||||||||||
| a (Å) | 167.6 | 167.3 | 170.7 | 168.7 | 170.7 | 171.0 | 169.0 | 168.7 | 170.7 | 166.7 | 166.7 |
| b (Å) | 111.2 | 110.6 | 111.6 | 111.6 | 115.5 | 115.0 | 110.9 | 111.6 | 111.6 | 110.1 | 110.1 |
| c (Å) | 155.4 | 154.2 | 157.2 | 156.2 | 157.6 | 157.5 | 156.5 | 156.2 | 157.2 | 155.7 | 155.7 |
| β (°) | 114.0 | 114.3 | 114.0 | 113.4 | 113.7 | 113.8 | 114.4 | 113.4 | 114.0 | 114.4 | 114.4 |
| s.d./unit-cell parameter‡ (%) | 0.56 | 0.36 | |||||||||
| Wavelength (Å) | 0.9000 | 1.2526 | 0.9000 | 0.9000 | 0.9790 | 0.9000 | 1.2526 | 0.9000 | 0.9000 | 0.9850 | 1.7000 |
| Resolution (Å) | 200–3.50 (3.63–3.50) | 200–6.00 (6.21–6.00) | 200–4.00 (4.14–4.00) | 200–7.00 (4.14–4.00) | 200–4.00 (4.14–4.00) | 200–4.00 (4.14–4.00) | 200–4.00 (4.14–4.00) | 200–4.00 (4.14–4.00) | 200–4.00 (4.14–4.00) | 200–3.50 (4.00–3.50) | 200–4.00 (4.50–4.00) |
| Observed reflections | 348035 (18261) | 41085 (3433) | 92816 (6526) | 33075 (3326) | 63815 (5358) | 61306 (4766) | 139511 (8088) | 60030 (4130) | 64219 (5005) | 109122 (36329) | 565283 (162661) |
| Independent reflections | 31138 (3095) | 6372 (613) | 22327 (2105) | 3964 (396) | 21392 (2061) | 21088 (1986) | 21177 (1881) | 20602 (1796) | 21088 (2002) | 31778 (10407) | 42471 (12574) |
| I/σ(I) | 26.1 (3.1) | 35.4 (6.2) | 15.3 (1.0) | 38.8 (14.2) | 13.1 (1.3) | 12.9 (1.3) | 20.2 (0.74) | 14.0 (0.65) | 9.3 (0.59) | 7.51 (0.56) | 13.53 (1.85) |
| Averaged redundancy | 11.2 (5.9) | 6.4 (4.5) | 4.2 (3.1) | 8.4 (8.4) | 3.0 (2.6) | 2.9 (2.4) | 6.6 (4.3) | 2.9 (2.3) | 3.0 (2.5) | 3.4 (3.4) | 13.3 (12.9) |
| Completeness (%) | 94.1 (94.9) | 97.1 (94.5) | 90.3 (95.1) | 91.6 (93.2) | 93.1 (90.4) | 91.3 (86.4) | 96.7 (87.6) | 99.1 (98.4) | 96.4 (92.3) | 97.4 (97.1) | 99.6 (99.2) |
| Rmerge§ (%) | 8.5 (37.8) | 5.2 (16.8) | 9.4 (70.8) | 5.9 (13.1) | 8.6 (68.5) | 7.0 (58.3) | 9.4 (>100) | 9.2 (93.2) | 11.0 (>100) | 10.6 (>100) | 14.4 (>100) |
| Refinement statistics | |||||||||||
| Rwork¶/Rfree | 0.337/0.351 | ||||||||||
| No. of atoms | 29595 | ||||||||||
| B factors (Å2) | 137.2 | ||||||||||
| R.m.s. deviations | |||||||||||
| Bond length (Å) | 0.012 | ||||||||||
| Bond angle (°) | 1.352 | ||||||||||
| Ramachandran plot (%) | |||||||||||
| Favoured region | 82.1 | ||||||||||
| Allowed region | 16.8 | ||||||||||
| Generously allowed region | 1.0 | ||||||||||
| Disallowed region | 0.0 | ||||||||||
†
Edge data and remote data were collected from the same crystal.
‡
The average of standard deviation/unit-cell parameter was calculated.
§
R
merge = 
, where I
i(hkl) is the intensity of the reflection and 〈I(hkl)〉 is the mean intensity of a group of equivalent reflections.
¶
R
work = 
, where F
o and F
c are the measured and calculated structure factors, respectively.