Crystallographic data and refinement statisticsa

Data setResult for:
EutL (zinc)EutM form IEutM form II
X-ray source (SSRL)BL 7-1BL 7-1BL 7-1
Cell dimensions (Å)a = 67.42, α = 90a = 70.0, α = 90a = 69.16, α = 90
b = 67.42, β = 90b = 149.25, β = 120.1b = 69.16, β = 90
c = 79.60, γ = 120c = 70.1, γ = 90c = 28.95, γ = 120
Resolution (Å) (high-resolution bin)58.42-2.65 (2.75-2.65)21.97-2.7 (2.8-2.7)17.29-2.0 (2.1-1.9)
Wavelength (Å)0.979460.949460.97946
Space groupP3P21P6
No. of reflections (unique)11,250 (847)56,948 (5418)4,477 (737)
No. of reflections (observed)31,465 (2383)117,751 (10775)49,593 (8935)
R-merge0.117 (0.363)0.03 (0.084)0.077 (0.229)
I/σ〈I3.9 (1.9)19.3 (9.0)21.45 (12.1)
Completeness (%)98.9 (98.3)84.1 (77.9)81.1 (98)
Redundancy2.8 (2.8)2.1 (1.9)11.1 (12.1)
RMSD bond angles1.971.991.99
RMSD bond lengths0.0220.0220.021
Ramchandran statistics (%)
  • a Rsym = Σ|I − 〈I〉|/Σ〈I〉, where I is the observed intensity and 〈I〉 is the statistically weighted average intensity of multiple symmetry related observation. R-factors: R = Σ‖Fcalc − |Fobs‖/Σ|Fobs|, where Fcalc and Fobs are the calculated and observed structure factors respectively. Rfree (4a) was calculated by the same formula with 7 % of randomly selected reflections. The data sets for EutL and EutM form II exhibited twinning, and refinements were carried out with the program REFMAC. The partial respective twin fractions for EutL (zinc) were 0.56 for twin operator h, k, l and for h, k, −l, 0.44 and those for EutM form I were for h, k, l 0.815 and −0.185 for −hk, k, −l. As described earlier (8), the degree of twinning varied among different crystals in both cases. Ramachandran statistics were obtained with the program PROCHECK (22a). RMSD, root mean square deviation from ideal geometry. The structure of EutM form I contains 12 EutM chains in the asymmetric unit, and it was collected to relatively low resolution. The six disordered C-terminal tails and His tags may have contributed to the relatively high Rfree value of this structure. As described in the text, data sets from all soaked crystals were obtained in triplicate and occasionally measured at other X-ray sources.