Table 2.

X-ray data collection and structure determination statistics

Data Collection
Wavelength, Å	0.97872
Resolution Range (high resolution bin), Å	30-2.70 (2.75-2.70)
Space Group	R3
Unit Cell (a, b, c (Å))	298.72, 298.72, 112.65
(α, β, γ (°))	90, 90, 120
Completeness, %	100.0 (100.0)
Total/Unique Reflections	578,608/101,147
Redundancy	5.7 (5.5)
<I/σI>	19.8 (5.3)
Rsyma, %	11.3 (34.8)
Refinement
Resolution, Å	30-2.70
Rwork/Rfreeb, %	18.9/21.4
Rms deviations
Bonds, Å	0.009
Angles, °	1.23
Ramachandran statistics, %
Most favored	89.8
Allowed	9.9
Generously allowed	0.3
Disallowed	0.0
# atoms
Protein	12,439
Water	296
Ligandc	14
<B factor>, Å2
Protein	27.5
Water	23.9
Ligandc	82.7

^aR_sym = ΣΣj|Ij − 〈I〉|ΣIj, where Ij is the intensity measurement for reflection j and 〈I〉 is the mean intensity for multiply recorded reflections.

^bR_work/R_free = Σ‖F_obs| − |F_calc‖/|F_obs|, where the working and free R factors are calculated by using the working and free reflection sets, respectively. The free R reflections (5% of the total) were held aside throughout refinement.

^cLigand refers to 7 zinc and 7 magnesium ions (one zinc and one magnesium for each of 7 monomers in the asymmetric unit).