Crystal structure of LIR-2 (ILT4) at 1.8 Å: differences from LIR-1 (ILT2) in regions implicated in the binding of the Human Cytomegalovirus class I MHC homolog UL18

Table 1 Data Collection and Refinement Statistics for LIR-2 D1D2

Space Group	P4₁2₁2
Unit Cell Dimensions (Å)	62.505, 62.505, 106.845
Data Collection
Resolution (Å)	34.1–1.8 (2.0–1.8)
Number of Observed Reflections	155116
Number of Independent Reflections	20290
^aCompleteness (%)	99.35 (100)
^bR_merge (%)	4.0 (33.0)
I/σ (I)	43.4 (5.9)
Refinement
Resolution (Å)	54.2–1.8
Reflections in working set	19241 (1405)
Reflections in test set	991, equivalent to 4.9%
^cR_cryst (%) 23.	23.4
^dR_free> (%)	27.3
Number of atoms
Protein	1559
	184 of 198 residues
Water	161
Average B factor	33.87 Å²
Anisotropic B correction
	B₁₁ = B₂₂ = 0.37 Å², B₃₃ = -0.74 Å²
Model Geometry
Rms deviation from ideality Bond lengths
Bond lengths (Å)	0.021
Bond angles (deg)	1.858
Ramachandran plot quality
Most favoured Region of Ramachandran plot (%)	91.90%
Additionally allowed Protein	8.10%
Generously allowed	0.0%
Disallowed	0.0%

^aCompleteness = (number of independent reflections/total theoretical number) ^bR_merge (I) = (Σ|I(i) - <I(h)>|/ΣI(i)), where I(i) is the i th observation of the intensity of the hkl reflection and <I> is the mean intensity from multiple measurements of the h,k,l reflection. ^cR_cryst (F) = Σ_h||F_obs(h)| - |F_calc(h)||/Σ_h|F_obs(h)| and |F_calc(h)| are the observed and calculated structure factor amplitudes for the h, k, l reflection. ^dR_free is calculated over reflections in a test set not included in atomic refinement. Figures in parentheses apply to data in the highest resolution shell.

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