Table 1. Refinement statistics.

Resolution range (Å)	25.0–2.1
No. of molecules in asymmetric unit	2
Rwork† (%)	20.9
Rfree‡ (%)	24.6
R.m.s.d. bond lengths (Å)	0.02
R.m.s.d. bond angles (°)	1.6
No. of reflections	22725
Ramachandran parameters
Residues in most favoured region (%)	84.2
Residues in allowed region (%)	14.2
Residues in generously allowed region (%)	1.6
Residues in disallowed region (%)	0.0
No. of non-H atoms used in refinement
Protein atoms	3504
Heterogen atoms	6
Solvent atoms	182
Average B factors (Å2)
Protein atoms	15.91
Heterogen atoms	19.35
Solvent atoms	21.13

^† R _work = for the 89.8% of the reflection data that were used in refinement.

^‡ R _free = for the remaining 10.2% of the reflection data that were not used in refinement.