Table 1.
New crystal structures of SRA-DNA complexes#
| Data collection | Crystal 1 | Crystal 2 | Crystal 3 |
| Space group | C2221 | P21 | |
| Cell dimensions | (α = β = γ = 90°) | α = γ = 90°, β = 98.9° | |
| a (Å) | 84.678 | 61.67 | 50.08 |
| b (Å) | 103.691 | 91.59 | 62.42 |
| c (Å) | 149.838 | 118.51 | 113.45 |
| Asymmetric unit | 2 complexes | 1 complex | 2 complexes |
| DNA | 5′-CCATGMGCTGAC-3′ 3′-GGTACGCGACTG-5′ |
||
| Beamline (SERCAT) | APS 22-ID | ||
| Wavelength (Å) | 1.00000 | ||
| Resolution (Å)* | 32.79-1.41 (1.45-1.41) |
29.91-1.99 (2.06-1.99) |
34.53-2.29 (2.37-2.29) |
| Rsym or Rmerge* | 0.095/0.771 | 0.102/0.568 | 0.102/0.352 |
| I/σI* | 10.9/1.0 | 9.0/3.6 | 10.5/2.3 |
| Completeness (%)* | 97.0/69.9 | 99.8/99.1 | 97.5/90.5 |
| Redundancy* | 5.1/1.7 | 9.6/6.5 | 3.4/2.9 |
| Observed reflections | 662,990 | 224,631 | 102,763 |
| Unique reflections* | 121,098 | 23,488 | 30,041 |
| Refinement | |||
| Resolution (Å) | 1.41 | 1.99 | 2.29 |
| No. reflections | 111,836 | 22,237 | 27,777 |
| Rwork/Rfree | 0.149/0.186 | 0.198/0.232 | 0.222/0.265 |
| Number of atoms | |||
| Protein | 3220 | 1609 | 3208 |
| DNA | 974 | 487 | 974 |
| Heterogen | 64 (ethylene glycol) |
54 (glycerol) |
- |
| Water | 596 | 162 | 150 |
| B-factors (Å2) | 17.8 | 28.8 | 35.1 |
| R.m.s. deviations | |||
| Bond lengths (Å) | 0.004 | 0.005 | 0.006 |
| Bond angles (°) | 1.1 | 1.1 | 1.1 |
| Dihedral angles (°) | 22.0 | 22.2 | 22.7 |
| Improper angles (°) | 0.99 | 0.96 | 1.08 |
| Estimated coordinate error | |||
| From Luzzati plot (Å) | 0.20 | 0.22 | 0.31 |
*
Highest resolution shell is shown in parenthesis.
#
Protein production, crystallization, X-ray data collection, structure determination and refinement were made as described {in ref. 19}.