Table 1. Data-collection and structure-refinement statistics.

Values in parentheses are for the highest resolution shell.

Data collection
Space group	P322	P1
Unit-cell parameters (Å, °)	a = 66.03, b = 66.03, c = 46.72, α = β = 90, γ = 120	a = 30.17, b = 41.32, c = 41.29, α = 80.05, β = 68.63, γ = 68.52
Molecules per ASU	1	2
Resolution range (Å)	20–2.20	20–1.75 (1.81–1.75)
Completeness (%)	97.9 (94.9)	91.5 (89.3)
I/σ(I)	10.4 (1.6)	9.3 (3.3)
Rmerge† (%)	4.65 (28.11)	4.92 (14.81)
Structure refinement
Resolution (Å)		20–1.75 (1.81–1.75)
Rcryst/Rfree‡ (%)		20.6 (33.0)/23.9 (34.0)
No. of protein atoms		1241
No. of waters		203
R.m.s.d. from ideal values
Bond lengths (Å)		0.015
Bond angles (°)		1.545
Average B factor (Å2)		27.3
Ramachandran plot (%)
Most favoured regions (%)		93.6
Allowed regions (%)		6.4

^† R _merge = , where I _i(hkl) is the intensity of the measured reflection and 〈I(hkl)〉 is the mean intensity of all symmetry-related reflections.

^‡ R _cryst = , where F _obs and F _calc are observed and calculated structure factors. R _free = , where T is a test data set of about 10% of the total reflections that were randomly chosen and set aside prior to refinement.