X-ray data collection (ESRF) and refinement statistics.

1values in parentheses are for the highest resolution shell.2, is the mean signal to noise ratio, where I is the integrated intensity of a measured reflection and σ is the estimated error in the measurement.3, where I is the integrated intensity of reflection h having i observations and is the mean recorded intensity of reflection h over multiple recording.4Rcryst = , where Fo are observed and Fc calculated structure factor amplitudes. Rfree is calculated from a randomly chosen 9.9% of reflections.