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Figure 1
Sequential data sets for wild-type AcNiR at 240 K, showing X-ray-induced reorganization of bound water molecules and the orientation of Ile257 at the T2Cu. The Cu ligands, Ile257 and proximal Asp98 residues are modelled in 2Fo − Fc electron-density maps contoured in the range 0.53–0.43 e Å−3. (a) ds1240K, the initial data set at 1.38 Å resolution, with two bound water molecules (W1 and W2) and two conformations (I and II) of the Ile257 side chain. Asp98 forms a ∼2.1 Å hydrogen bond to W1. (b) ds2240K at 1.47 Å resolution, with the W1 site vacated, leaving one bound water W2 and with both Ile257 conformations I and II present. (c) ds3240K at 1.65 Å resolution, with W2 and Ile257 present only in conformation I. (d) Comparison of the ds1240K (red), ds2240K (green) and ds3240K (blue) serial structures, showing `migration' of W2 into the centre of the T2Cu cavity, occupying in ds3240K the space freed by the absence of Ile257 conformation II.

IUCrJ
Volume 4| Part 4| July 2017| Pages 495-505
ISSN: 2052-2525
https://doi.org/10.1107/S2052252517007527