Table I.

Crystallographic data, phasing, and refinement

Beamline: Advanced Light Source 8.3.1
Space group: P21Cell dimensions: a=33.1 Å, b=37.3 Å, c=56.9 Å, α=90°, β=106.1°, γ=90°Phasing Powerb
Data Statistics:dmin (Å)Completeness (%)I/σRsym (%)a+Friedel mate−Friedel mate
SeMet λ1 (0.97964 Å)2.0092.8 (83.8)25.2 (6.4)3.4 (13.4)0.27 (0.17)0.81 (0.54)
SeMet λ2 (0.97979 Å)2.0093.6 (80.8)23.1 (2.4)3.8 (31.9)2.05 (0.71)2.05 (0.76)
SeMet λ3 (1.12713 Å)2.0082.3 (40.4)25.4 (6.1)3.0 (13.3)Reference0.35 (0.17)
Figure of meritc:centrics: 0.81 (0.59)acentrics: 0.57 (0.25)
Refinement:(50–2.0 Å)
R Valued:21.9 (20.3)
Rfreee:25.1 (23.3)
Rmsd bond lengths (Å):0.006
Rmsd bond angles (°):0.92
Mean B factor (min/max):28.1 Å2 (7.9 Å2/65.7 Å2)
Space group: C2221Cell dimensions: a=33.1 Å, b=108.3 Å, c=37.2 Å, α=90°, β=90°, γ=90°Phasing Powerb
Data Statistics:dmin (Å)Completeness (%)I/σRsym (%)a+Friedel mate−Friedel mate
Native (1.12704 Å)1.8097.2 (87.1)49.5 (11.2)2.9 (14.1)
SeMet λ1 (0.97973 Å)2.0092.1 (88.6)20.9 (3.3)4.8 (25.7)1.74 (0.68)1.89 (0.74)
SeMet λ2 (0.99987 Å)2.0092.1 (83.9)22.8 (3.8)4.3 (21.3)Reference0.29 (0.12)
Figure of meritc:centrics: 0.70 (0.43)acentrics: 0.52 (0.20)
Refinement:(50–1.8 Å)
R valued:22.1 (24.9)
Rfreee:25.9 (28.8)
Rmsd bond lengths (Å):0.004
Rmsd bond angles (°):0.82
Mean B factor (min/max):24.2 Å2 (12.0 Å2/58.5 Å2)
  • a Rsym = ShΣi|Ii(h),I(h)>|/ ΣhΣiIi(h), where Ii(h) is the integrated intensity of the ith reflection with the Miller Index h, and <I(h)> is the average over Friedel and symmetry equivalents.

  • b Mad phasing power is defined as [<|FDFN|2>/P(ϕ)(||FNIeFh|FD|2)dϕ]1/2, where P(ϕ) is the experimental phase probability distribution. FN are structure factors at the designated reference wavelength and FD are structure factors of + or − Friedel mates at the other designated wavelength. ΔFh is the difference in heavy atom structure factors between two wavelengths.

  • c Figure of merit is the weighted mean of the cosine of the deviation from αbest.

  • d R value = Σ(|Fobs|−k|Fcalc|)/Σ|Fobs|.

  • e Rfree is calculated using a 10% subset of the data that is removed randomly from the original data and excluded from refinement.

  • Values in parentheses are for the highest resolution shells.