TABLE 2.

X-ray data collection and refinement statistics

Numbers in parentheses refer to the highest resolution shell.

Data collection
Space group	C2221
Unit cell edges (Å)	a = 138.6, b = 197.6, c = 83.0
X-ray source	ESRF BM-14
Resolution range (Å)	30-2.5 (2.57-2.50)
No. of unique observations	37,806
Completeness (%)	95.4 (88.6)
Redundancy	4.9 (3.2)
Rmergea	0.064 (0.414)
<I/σI>	15.8 (2.7)
Refinement
No. of reflections work/test	35,893/1,911
No. of protein atoms	4,433
No. of ligand atoms	129
No. of waters	137
Average B-factors (Å2)
Protein monomers A/B/C	42.4/43.9/50.1
3′SL ligands/waters	66.7/43.5
Rcrystb	0.224
Rfree	0.263
Root mean square deviation bond distance (Å)	0.017
Root mean square deviation bond angle (°)	1.716

^aR_merge = ∑_hkl ∑_i|I_{hkl, i} - 〈I_hkl〉|/∑_hkl〈I_hkl〉.

^bR_cryst and R_free = (∑||F_o| - |F_c||)/(∑|F_o|).