Crystal structure of stringent starvation protein A (SspA), an RNA polymerase-associated transcription factor
X-RAY DIFFRACTION
Crystallization
| Crystalization Experiments | ||||
|---|---|---|---|---|
| ID | Method | pH | Temperature | Details |
| 1 | VAPOR DIFFUSION, HANGING DROP | 7.5 | 291 | diammonium hydrogen citrate, PEG 3350, pH 7.5, VAPOR DIFFUSION, HANGING DROP, temperature 291K |
| Crystal Properties | |
|---|---|
| Matthews coefficient | Solvent content |
| 2.654 | 51.87 |
Crystal Data
| Unit Cell | |
|---|---|
| Length ( Å ) | Angle ( ˚ ) |
| a = 100.412 | α = 90 |
| b = 100.412 | β = 90 |
| c = 181.89 | γ = 120 |
| Symmetry | |
|---|---|
| Space Group | P 65 2 2 |
Diffraction
| Diffraction Experiment | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ID # | Crystal ID | Scattering Type | Data Collection Temperature | Detector | Detector Type | Details | Collection Date | Monochromator | Protocol | |||||
| 1 | 1 | x-ray | 100 | CCD | ADSC QUANTUM 4 | mirrors | 2002-02-19 | M | SINGLE WAVELENGTH | |||||
| Radiation Source | |||||
|---|---|---|---|---|---|
| ID # | Source | Type | Wavelength List | Synchrotron Site | Beamline |
| 1 | SYNCHROTRON | NSLS BEAMLINE X9B | 1.06129 | NSLS | X9B |
Data Collection
| Overall | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ID # | Resolution (High) | Resolution (Low) | Percent Possible (Observed) | R Merge I (Observed) | Net I Over Average Sigma (I) | Redundancy | Number Reflections (All) | Number Reflections (Observed) | Observed Criterion Sigma (F) | Observed Criterion Sigma (I) | B (Isotropic) From Wilson Plot | ||||||||
| 1 | 2.02 | 30 | 100 | 0.108 | 16.12 | 6.97 | 36005 | 21 | |||||||||||
| Highest Resolution Shell | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ID # | Resolution (High) | Resolution (Low) | Percent Possible (All) | Percent Possible (Observed) | R Merge I (Observed) | Mean I Over Sigma (Observed) | Redundancy | Number Unique Reflections (All) | |||||||||||
| 2.02 | 2.09 | 97.4 | 0.519 | 2.83 | 5.61 | 3455 | |||||||||||||
Refinement
| Statistics | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Diffraction ID | Structure Solution Method | Cross Validation method | Resolution (High) | Resolution (Low) | Number Reflections (All) | Number Reflections (Observed) | Number Reflections (R-Free) | Percent Reflections (Observed) | R-Factor (All) | R-Factor (Observed) | R-Work (Depositor) | R-Work (DCC) | R-Free (Depositor) | R-Free (DCC) | R-Free Selection Details | Mean Isotropic B | |||
| X-RAY DIFFRACTION | MIR | THROUGHOUT | 2.02 | 29.46 | 36005 | 36005 | 1785 | 99.4 | 0.181 | 0.181 | 0.179 | 0.17 | 0.215 | 0.21 | RANDOM | 25.2 | |||
| Temperature Factor Modeling | ||||||
|---|---|---|---|---|---|---|
| Anisotropic B[1][1] | Anisotropic B[1][2] | Anisotropic B[1][3] | Anisotropic B[2][2] | Anisotropic B[2][3] | Anisotropic B[3][3] | |
| -0.94 | 0.32 | -0.94 | 1.88 | |||
| RMS Deviations | |
|---|---|
| Key | Refinement Restraint Deviation |
| c_dihedral_angle_d | 21.2 |
| c_scangle_it | 5.61 |
| c_scbond_it | 4.37 |
| c_mcangle_it | 3.41 |
| c_mcbond_it | 2.61 |
| c_angle_deg | 1.3 |
| c_improper_angle_d | 0.92 |
| c_bond_d | 0.009 |
| Non-Hydrogen Atoms Used in Refinement | |
|---|---|
| Non-Hydrogen Atoms | Number |
| Protein Atoms | 3333 |
| Nucleic Acid Atoms | |
| Solvent Atoms | 441 |
| Heterogen Atoms | 26 |
Software
| Software | |
|---|---|
| Software Name | Purpose |
| SOLVE | phasing |
| SHARP | phasing |
| CNS | refinement |
| DENZO | data reduction |
| SCALEPACK | data scaling |














