Table 1.

Crystallographic analysis (MIR and MAD phasing) and refinement statistics of ERA protein

	Resolution, Å	Redundancy,* Å	Completeness (last shell), (%)	Rsym†	# Sites	Rscale‡	Phasing power§
							Centric, iso	Acentric, iso/ano
Native data	2.4	6.4	99.7 (99.1)	0.056
MIR phasing (mean figure of merit = 0.71)
EMP (Tris buffer)	3.5	3.2	96.3  (82.9)	0.086	4	0.216	1.4	1.9/1.2
EMP (Hepes buffer)	2.95	3.5	98.3  (97.1)	0.075	8	0.130	1.3	1.7/0.94
APMA	4.0	2.8	97.5  (97.9)	0.098	4	0.201	0.98	1.3/0.90
(UO2)(NO3)2	3.2	3.2	98.8  (98.8)	0.084	2	0.080	0.34	0.28/0.26
MAD phasing (EMP, mean figure of merit = 0.81)
λ1 = 1.00870 Å	2.6	5.4	99.4  (99.1)	0.064	4	0.023	1.7	2.1/2.6
λ2 = 1.00764 Å	2.6	5.5	99.5  (99.1)	0.070	4	0.022	1.3	1.6/2.3
λ3 = 0.99184 Å	2.6	5.6	99.5  (99.2)	0.076	4	0.034	n.a.	n.a./2.6
λ4 = 1.00903 Å	2.6	5.7	99.5  (99.1)	0.063	4	0.034	1.1	1.5/2.0
Structure refinement
Resolution (Å), 8-2.4
Reflections (I/σ(I) > 2), 28, 848
Completeness (last shell), 82.9 (56.9)
R/Rfree, 0.243/0.298
rms deviations, bond/angle, 0.009 Å/1.55°
Protein atoms, 4,618
Sulfate ions, 5
Water molecules, 150

APMA, 4-aminophenylmercuric acetate. n.a., not applicable. 

¹⁷⁸Redundancy is the average number of observations for each unique reflection. 

^†R_sym = Σ|I_n − 〈I_n〉|/ΣI_n, where 〈I_n〉 is the average intensity over symmetric equivalents. 

^‡R_scale = Σ|I_PH − I_P|/ΣI_P. 

^§Phasing power 〈f_h〉/〈E〉, where 〈f_h〉 and 〈E〉 are the rms deviation of the heavy-atom structure factor and the lack of closure error, respectively.