TABLE 1.

Data collection and refinement statistics

Data set (PDB code)	Phasing	pH 8.5 (4KNT)	pH 6.5 (4KNU)	pH 6.5 reduced (4KNS)
Data collection
Space group	C2	C2	P21	P21
Cell dimensions	a = 100, b = 123, and c = 88 Å; γ = 97°	a = 100, b = 123, and c = 88 Å; γ = 97°	a = 51, a = 137, and c = 121 Å; γ = 101°	a = 51, b = 138, and c = 120 Å; γ = 101°
Resolution (Å)a	2.4 (2.49–2.40)	1.9 (1.90–1.95)	1.8 (1.80–1.85)	2.2 (2.20–2.26)
Rsyma,b	0.191 (0.387)	0.096 (0.443)	0.120 (0.463)	0.112 (0.530)
I/σIa	11.7 (3.4)	15.2 (2.8)	11.5 (2.3)	11.6 (2.1)
Completeness (%)a	100 (100)	98.6 (94.5)	99.6 (98.1)	91.0 (91.7)
Refinement
Rworkc/Rfreed		16.9/20.0	17.1/20.9	18.5/22.9
Ramachandran outliers (%)		0	0	0
Average B-factor		19.6	14.4	27.1
r.m.s.d.e
Bond lengths (Å)		0.006	0.008	0.005
Bond angles		0.609°	1.244°	0.923°

^a Values in parentheses refer to the highest resolution shell.

^b R_sym = Σ|I_obs − I_av|/ΣF_obs, where the summation is over all reflections.

^c R_work = Σ|F_obs − F_calc|/ΣF_obs.

^d For calculation of R_free, 5% of the reflections were reserved.

^e r.m.s.d., root mean square deviation.