2QRT

Crystal Structure of a disulfide trapped single chain trimer composed of the MHC I heavy chain H-2Kb Y84C, beta-2microglobulin, and ovalbumin-derived peptide.

X-RAY DIFFRACTION

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	6.3	298	13% PEG 6000, 100 mM MES, pH 6.3, VAPOR DIFFUSION, HANGING DROP, temperature 298K

Crystal Properties
Matthews coefficient	Solvent content
2.61	52.92

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 66.6	α = 90
b = 89.1	β = 110.9
c = 88.6	γ = 90

Symmetry
Space Group	P 1 21 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	ADSC QUANTUM 315		2004-10-01	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	APS BEAMLINE 19-ID	0.98	APS	19-ID

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (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	1.75	50		0.058	30.1	6.8		96928

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)
	1.75	1.81			0.491	2.61

Refinement

Statistics
Diffraction ID	Structure Solution Method	Starting model	Resolution (High)	Resolution (Low)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Work	R-Free	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	PDB entry 1RJY	1.8	20	89351			0.208	0.239	35.946

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]

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	6388
Nucleic Acid Atoms
Solvent Atoms	755
Heterogen Atoms

Software

Software
Software Name	Purpose
CNS	refinement
PDB_EXTRACT	data extraction
HKL-3000	data collection
HKL-3000	data reduction
HKL-3000	data scaling
CNS	phasing

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.