1UNS

IDENTIFICATION OF A SECONDARY ZINC-BINDING SITE IN STAPHYLOCOCCAL ENTEROTOXIN C2: IMPLICATIONS FOR SUPERANTIGEN RECOGNITION

X-RAY DIFFRACTION

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Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
experimental model	PDB	1STE	PDB ENTRY 1STE

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1		6.5		pH 6.50

Crystal Properties
Matthews coefficient	Solvent content
2.26	45.46

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 42.5	α = 90
b = 44.54	β = 90
c = 131.65	γ = 90

Symmetry
Space Group	P 21 21 21

Diffraction

Diffraction Experiment
ID #	Crystal ID	Scattering Type	Data Collection Temperature	Detector	Detector Type	Details	Collection Date	Monochromator	Protocol
1	1	x-ray	289	IMAGE PLATE	MARRESEARCH			M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	SRS BEAMLINE PX9.5		SRS	PX9.5

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	40	91.4	0.078		4.9		16364		-3

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Starting model	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	MOLECULAR REPLACEMENT	THROUGHOUT	PDB ENTRY 1STE	2	8	18932		97.9	0.1982	0.1982	0.2254	RANDOM	19.9

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]

RMS Deviations
Key	Refinement Restraint Deviation
c_mcangle_it	2
c_scangle_it	2
c_mcbond_it	1.5
c_scbond_it	1.5
c_angle_deg	1.18
c_bond_d	0.0059
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
c_dihedral_angle_d_na
c_dihedral_angle_d_prot
c_improper_angle_d
c_improper_angle_d_na
c_improper_angle_d_prot

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	1893
Nucleic Acid Atoms
Solvent Atoms	77
Heterogen Atoms	2

Software

Software
Software Name	Purpose
CNS	refinement
DENZO	data reduction
SCALEPACK	data scaling