Table 1.

Electron crystallographic data

Two-side plane group	p4212
Unit cell dimension	a = b = 99.58 ± 0.50 Å, c = 100 Å
IQ cut-off* of data	≤ 7
Number of observed amplitudes	48,037
Number of observed phases	19,839
Number of structure factors	2,947
Overall completeness† (100–3.7 Å)	63%
In-plane resolution	3.7 Å
Estimated resolution normal to the bilayer‡	6 Å
Overall phase residual	25.7°
Electron diffraction
Resolution limit	3.3 Å
Maximum tilt	57.5°
Number of patterns	44
RFriedel§	6.7–28.9% (15.8%)
Rmerge¶	15.4–47.3% (27.5%)
Image
Resolution limit	3.7 Å
Maximum tilt	60.2°
Number of images	72
Phase residual‖ in  resolution zones	(100–7.0 Å) 20.0°
	(7–4.0 Å) 39.7°
	(4.0–3.7 Å) 55.7°
Overall	(100–3.7 Å) 25.7°
Refinement statistics
Rfactor**	35.0%
Rfree**	45.1%
φfree‡‡	62.4°

^*Nomenclature of Henderson et al. (43). 

^† With figure of merit ≥ 0.27. Maximum completeness for data up to 60° tilt is 83%. 

^‡ Based on calculation of point-spread function (44) for the experimental map. 

^§ R_Friedel = ∑_hk|I_hk − I_h̄k̄|/∑_hk(I_hk + I_h̄k̄), average in parentheses. 

^¶ R_merge = ∑_hk|I_obs − I_fit|/∑_hkI_fit, average in parentheses. 

^‖ Weighting based on amplitudes. 

^**Using electron diffraction amplitudes (≥ 2σ) between 24 and 3.7 Å. 

^‡‡ Averaged difference between phases calculated from the model and the observed phases with figure of merit ≥ 0.50.