1HSA

THE THREE-DIMENSIONAL STRUCTURE OF HLA-B27 AT 2.1 ANGSTROMS RESOLUTION SUGGESTS A GENERAL MECHANISM FOR TIGHT PEPTIDE BINDING TO MHC

X-RAY DIFFRACTION

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Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1				THE FRAGMENT CRYSTALLIZED WAS THE EXTRACELLULAR PORTION OF THE PROTEIN CLEAVED FROM DETERGENT MICELLES WITH PAPAIN

Crystal Properties
Matthews coefficient	Solvent content
2.83	56.54

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 45.1	α = 80.3
b = 69.8	β = 88.6
c = 81.1	γ = 89.9

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

Refinement

Statistics
Diffraction ID	Structure Solution Method	Resolution (High)	Resolution (Low)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Factor (Observed)	R-Work	R-Free	Mean Isotropic B
X-RAY DIFFRACTION		2.1				0.203	0.203

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	2.8
x_bond_d	0.016
x_bond_d_na
x_bond_d_prot
x_angle_d
x_angle_d_na
x_angle_d_prot
x_angle_deg_na
x_angle_deg_prot
x_dihedral_angle_d
x_dihedral_angle_d_na
x_dihedral_angle_d_prot
x_improper_angle_d
x_improper_angle_d_na
x_improper_angle_d_prot
x_mcbond_it
x_mcangle_it
x_scbond_it
x_scangle_it

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	6266
Nucleic Acid Atoms
Solvent Atoms	440
Heterogen Atoms

Software

Software
Software Name	Purpose
X-PLOR	model building
X-PLOR	refinement
X-PLOR	phasing