TABLE 1.

Data collection and processing^a

Parameter	Result(s)
Data collection
Synchrotron station	SRS 14.1
Wavelength (Å)	1.488
Space group	P21
Cell dimensions	a = 55.35 Å, b = 107.99 Å, c = 55.65Å, α = 90°, β = 92.14°, γ = 90°
Maximal resolution (Å)	1.70
Highest-resolution bin (Å)	1.79–1.70
No. of observations	217,593 (31,047)
No. of unique reflections	71,591 (10,454)
Completeness (%)	99.9 (99.9)
Rmergeb	0.075 (0.295)
I/σ(I)	5.1 (2.4)
Refinement
No. of protein atomsc	3,483
No. of residues, chains A, B, and C	204–355
No. of water molecules	531
No. of calcium ions	9
No. of ligand atoms	44
Rworkd (%)	19.2
Rfreee (%)	21.0
RMSD bond length (Å)	0.007
RMSD bond angle (°)	1.2
Average B-values (Å2)
Protein main chain	21.6
Water	33.3
Other heteroatoms	29.4
Ramachandran plot valuesf (%)
Favored	98.0
Outliers	0.0

^aNumbers in parentheses refer to the highest-resolution bin. RMSD, root mean square deviation.

^bR_merge = Σ_hΣ_j |I_h,_j − I_h|/Σ_hΣ_j |I_h,_j|, where I_h,_j is the jth observation of reflection h and I_h is the mean of the j measurements of reflection h.

^cExcluding alternative side chain conformations.

^dR_work = Σ_h ||F_oh| − |F_ch||/Σ_h |F_oh|, where F_oh and F_ch are the observed and calculated structure factor amplitudes, respectively, for reflection h.

^eR_free is equivalent to R_work for a randomly selected subset (5%) of reflections not used in the refinement.

^fDefined according to Molprobity.