3E5C

Crystal Structure of the SMK box (SAM-III) Riboswitch with SAM

X-RAY DIFFRACTION

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Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	7	298	40 mM sodium cacodylate, 80 mM SrCl, 15% MPD, 2 mM spermine-HCl, pH 7, VAPOR DIFFUSION, HANGING DROP, temperature 298K

Crystal Properties
Matthews coefficient	Solvent content
2.99	58.91

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 97.806	α = 90
b = 97.806	β = 90
c = 87.138	γ = 90

Symmetry
Space Group	I 41 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 315		2007-11-21	M	SINGLE WAVELENGTH
2	1	x-ray	100	CCD	ADSC QUANTUM 210		2007-10-22	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	APS BEAMLINE 24-ID-E	0.9792	APS	24-ID-E
2	SYNCHROTRON	CHESS BEAMLINE F1	0.918	CHESS	F1

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (Observed)	R Merge I (Observed)	R Sym 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	2.25	20	93.3	0.069	0.065	24.7	9.8		9607		37.1	47.8

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	R Merge I (Observed)	R-Sym I (Observed)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
	2.25	2.35	74		0.37	0.417	1.6	4.7	666

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Resolution (High)	Resolution (Low)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Factor (Observed)	R-Work	R-Free	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	SAD+MR	THROUGHOUT	2.25	19.9	9607	460	93.3	0.221	0.221	0.227	RANDOM	54.5

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]
-8.63			-8.63		17.26

RMS Deviations
Key	Refinement Restraint Deviation
c_dihedral_angle_d	19.2
c_angle_deg	1.7
c_improper_angle_d	1.54
c_bond_d	0.011
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
c_mcbond_it
c_mcangle_it
c_scbond_it
c_scangle_it

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms
Nucleic Acid Atoms	1155
Solvent Atoms	69
Heterogen Atoms	42

Software

Software
Software Name	Purpose
CNS	refinement
HKL-2000	data collection
HKL-2000	data reduction
HKL-2000	data scaling
PHASER	phasing