Table 1.

Crystallographic data reduction and phasing statistics.

Crystal*	Resolution (Å)	No. of observations	No. of unique reflections	Rmerge†	I/σI	Completeness (%)	Phasing power‡	Anomalous Rcullis§
CynSeMet (1.0332 Å)	20–1.65	524,489	187,107	3.9 (19.8)	26.4 (3.9)	94.2 (80.6)	–	–
CynSeMet λ1 (1.0781 Å)	20–2.40	211,456	55,582	2.7 (4.2)	38.0 (32.0)	87.0 (42.6)	2.17	0.95
CynSeMet λ2 (0.9795 Å)#	20–2.40	242,516	63,330	4.5 (6.4)	35.2 (22.9)	97.6 (79.6)	0.0	0.65
CynSeMet λ3 (0.9793 Å)	20–2.40	209,172	63,118	5.9 (7.9)	36.3 (28.3)	97.5 (80.4)	1.29	0.46
CynSeMet λ4 (0.9465 Å)	20–2.40	242,869	62,595	2.3 (2.9)	26.3 (24.1)	96.7 (97.7)	1.42	0.61
CynSeMet-Oxl (1.0332 Å)	20–1.65	436,555	190,231	4.7 (17.1)	21.5 (4.3)	95.4 (79.4)	–	–

^*CynSeMet, selenomethionine-labeled cyanase (unit-cell parameters a = 76.3 Å, b = 81.0 Å, c = 82.3 Å, α = 70.3°, β = 72.2°, γ = 66.4°). CynSeMet-Oxl, CynSeMet soaked with sodium oxalate (unit-cell parameters a = 76.3 Å, b = 80.9 Å, c = 82.1 Å, α = 70.1°, β = 71.9°, γ = 66.4°; see text). λ1, low-energy remote data set; λ2, inflection point data set; λ3, peak data set: λ4, high-energy remote data set. The wavelengths used to collect these data are shown in parentheses.

^†R_merge =Σ_hkl Σ_{i = l}^N |〈I^hkl〉 – I_i^hkl| /Σ_hkl Σ_{i = l}^N I_i^hkl.

^‡Phasing power = <F_h>/<LOC>, where <F_h> and <LOC> are the root mean square heavy-atom structure factor and lack of closure, respectively.

^§R_cullis = Σ∥F_ph(obs) ± |Fp (obs)∥ – |F_h(calc)|/Σ ∥F_ph (obs)| ± |F_p (obs)∥, where F_ph, F_p and F_h are the structure-factor amplitudes for the heavy-atom derivative, the native protein, and the heavy-atom contribution, respectively.

^#The λ2 data were taken as the reference data set for phase refinement with MLPHARE [46].