Data collection and refinement statistics.

aValues in parentheses correspond to the highest resolution data shell.
bR = merge∑∑I(h)j−< I(h>∑∑)/ I(h)j where I(h)j is the measured diffraction intensity and the summation includes all observations.
cAll positive reflections were used in the refinement.
dRwork is = ∑| the R-factor(Fo|−∑| Fc|∑|)/Fo| where Fo and Fc are observed and calculated structure factors, respectively.
eRfree% is the R-factor calculated using 5 of the data that were excluded from the refinement.
fThe r.m.s deviation is the root-mean-square deviation from ideal geometry of protein.