1LY2

Crystal structure of unliganded human CD21 SCR1-SCR2 (Complement receptor type 2)

X-RAY DIFFRACTION

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	7.5	298	PEG 4000, pH 7.5, VAPOR DIFFUSION, HANGING DROP at 298K, temperature 298.0K

Crystal Properties
Matthews coefficient	Solvent content
2.48	50.41

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 31.6	α = 91.51
b = 33.27	β = 111.44
c = 42.11	γ = 117.81

Symmetry
Space Group	P 1

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	CUSTOM-MADE	wiggler	2001-02-01	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	NSLS BEAMLINE X25	1.05	NSLS	X25

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (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	1.8	30	88.4			12743	11265

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	R-Sym I (Observed)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
1	1.8	1.9	55.8		0.1

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Starting model	Resolution (High)	Resolution (Low)	Number Reflections (All)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Work	R-Free	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	THROUGHOUT	Crystal structure of liganded CD21 (complex with C3d)	1.8	20	12743	11265	1127		0.179	0.234	random

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
x_angle_deg	1.34
x_bond_d	0.007

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	996
Nucleic Acid Atoms
Solvent Atoms	146
Heterogen Atoms	28

Software

Software
Software Name	Purpose
DENZO	data reduction
SCALEPACK	data scaling
AMoRE	phasing
X-PLOR	refinement

RCSB PDB Core Operations are funded by the National Science Foundation (DBI-1832184), the US Department of Energy (DE-SC0019749), and the National Cancer Institute, National Institute of Allergy and Infectious Diseases, and National Institute of General Medical Sciences of the National Institutes of Health under grant R01GM133198.