3IQN

Free-state structural transitions of the SAM-I riboswitch

X-RAY DIFFRACTION

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Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
experimental model	PDB	2GIS	PDB entry 2GIS

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	hanging drop	7	303	pH 7.0, hanging drop, temperature 303K

Crystal Properties
Matthews coefficient	Solvent content
2.5	50.75

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 61.98	α = 90
b = 61.98	β = 90
c = 159.07	γ = 90

Symmetry
Space Group	P 43 21 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	IMAGE PLATE	RIGAKU RAXIS IV++		2007-06-24	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	ROTATING ANODE	OTHER	1.5418

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	2.7	20	99.8	0.073	12.4	3.74		16190			34.2

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)
	2.7	2.8	100		0.278	4.6	3.68

Refinement

Statistics
Diffraction ID	Structure Solution Method	Starting model	Resolution (High)	Resolution (Low)	Number Reflections (All)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Factor (Observed)	R-Work	R-Free	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	PDB entry 2GIS	2.7	20	16219	16027	1529	98.8	0.259	0.259	0.299	50.61

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]
10.68			10.68		-21.36

RMS Deviations
Key	Refinement Restraint Deviation
c_dihedral_angle_d	20.3
c_scangle_it	2.2
c_improper_angle_d	2.1
c_mcangle_it	1.8
c_angle_deg	1.4
c_scbond_it	1.38
c_mcbond_it	1.25
c_bond_d	0.007
c_bond_d_na
c_bond_d_prot
c_angle_d
c_angle_d_na
c_angle_d_prot
c_angle_deg_na
c_angle_deg_prot
c_dihedral_angle_d_na
c_dihedral_angle_d_prot
c_improper_angle_d_na
c_improper_angle_d_prot

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms
Nucleic Acid Atoms	2031
Solvent Atoms	33
Heterogen Atoms	38

Software

Software
Software Name	Purpose
d*TREK	data scaling
CNS	refinement
PDB_EXTRACT	data extraction
CrystalClear	data collection
d*TREK	data reduction
CNS	phasing