TABLE 1.

Crystallographic data and refinement statistics

Statistics	Dataset I: NirE + SAH	Dataset II: NirE + SAH + uro'gen III
Data collection
Beamline	Rigaku MircoMax 007HF	BESSY (BL14.2)
Wavelength (Å)	1.541	0.91841
Resolution (Å)a	46.3-2.0 (2.05-2.00)	35.0-2.0 (2.05-2.00)
Space group	C2221	C2221
Unit cell parameters
a, b, c (Å)	60.9, 115.1, 76.8	60.9, 116.2, 77.1
α, β, γ (°)	90, 90, 90	90, 90, 90
Unique reflectionsa	19,360 (1,411)	18,362 (1,418)
Multiplicitya	4.4 (4.5)	3.9 (4.0)
Completeness (%)a	99.82 (99.86)	92.6 (99.9)
I/σIa	20.19 (2.58)	22.8 (4.0)
Rmergea,b	0.043 (0.586)	0.083 (0.451)
Wilson B (Å2)	35.1	34.4
Solvent content (%)	46.4	49.7
Refinement
Rworkc	0.2349	0.2169
Rfreed	0.2868	0.2526
No. of atoms
Protein	1,864	1,825
Ligand	26	86
Water	195	129
Total	2,085	2,040
Atomic displacement factors B (Å2)e
Overall	21.4	33.6
Protein	21.4	33.7
SAH	23.6	22.7
Uro'gen III		58.8
Water	21.4	24.0
Molecules per asymmetric unit	1/1/0	1/1/1
(NirE/SAH/uro'gen III)
Real space correlation coefficientsf
Total	0.7676	0.7806
Protein
Backbone	0.8204	0.8546
Side chains	0.7848	0.8232
SAH	0.9314	0.9427
Uro'gen III		0.7769
Root mean square deviation from ideal
Bond lengths (Å)	0.0239	0.0219
Bond angles (°)	2.167	1.935
Ramachandran plot
Favored (%)	97.1	97.0
Allowed (%)	2.9	3.0
Disallowed (%)	0.0	0.0

^a Values in parentheses account for the highest resolution shell.

^b R_merge = Σ| I_o−〈I〉|/ΣI_o.

^c R_work = (Σ‖F_o|−|F_c‖/Σ|F_o|); |F_o|, structure factor magnitudes observed; |F_c|, structure factors calculated.

^d R_free is computed as R_work but using 5% randomly assigned reflections excluded from refinement.

^e These B factors constitute the total B factors representing isotropic (thermal) and anisotropic (domain) movement.

^f Real space correlation coefficient (RSCC) = Σ|ρ_o−〈ρ_o〉|Σ|ρ_c − 〈ρ_c〉|/(Σ| ρ_o−〈ρ_o〉|²Σ|ρ_c−〈ρ_c〉²|)^1/2; ρ, electron density values at grid points that cover the molecule in question; ρ_o, experimental electron density; ρ_c, model density.