5TRU

Structure of the first-in-class checkpoint inhibitor Ipilimumab bound to human CTLA-4

Experimental procedure

Experimental method	SINGLE WAVELENGTH
Source type	SYNCHROTRON
Source details	APS BEAMLINE 24-ID-E
Synchrotron site	APS
Beamline	24-ID-E
Temperature [K]	100
Detector technology	CCD
Collection date	2009-08-02
Detector	ADSC QUANTUM 315
Wavelength(s)	0.979
Spacegroup name	C 2 2 21
Unit cell lengths	95.844, 197.502, 148.117
Unit cell angles	90.00, 90.00, 90.00

Refinement procedure

Resolution	34.910 - 3.000
R-factor	0.2067
Rwork	0.203
R-free	0.26770
Structure solution method	MOLECULAR REPLACEMENT
Starting model (for MR)	1i85
RMSD bond length	0.009
RMSD bond angle	1.461
Data reduction software	HKL-2000
Data scaling software	SCALEPACK
Phasing software	MOLREP
Refinement software	REFMAC (5)

Data quality characteristics

	Overall	Inner shell	Outer shell
Low resolution limit [Å]	34.910	50.000	3.050
High resolution limit [Å]	3.000	8.130	3.000
Rmerge	0.143	0.058	0.820
Total number of observations	181876
Number of reflections	28514
<I/σ(I)>	6.1
Completeness [%]	99.7	97.6	99.9
Redundancy	6.4	5.7	6.6

Crystallization Conditions

crystal ID	method	pH	temperature	details
1	VAPOR DIFFUSION	7.5	291	0.1M ammonium sulfate, 0.1M Tris pH 7.5, 20% PEG 1500