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Figure 3
MSOX movie of catalysis in AcNiR at room temperature. A ten-frame X-ray-induced `movie' recorded from consecutive serial data sets showing conversion at the T2Cu site of bound nitrite to NO and then to the H2O resting state. Initially in ds1RT the nitrite is bound to T2Cu in the `top-hat' orientation (a), but this rapidly changes in ds2RT to a progressively more `side-on' orientation (b, c and d). The `side-on' nitrite is converted to NO by ds5RT (e) and the NO is replaced by water at ds10RT (j). Only the proximal position of Asp98 is observed in this sequence of electron-density maps. Asp98, His100, His135, nitrite and NO are represented as sticks, and water molecules and Cu atoms as spheres. Other T2Cu-site residues are omitted for simplicity. The 2FobsFcalc density in e Å−3 is contoured at 0.45 (ds1RT), 0.43 (ds2RT), 0.39 (ds3RT–ds7RT) and 0.38 (ds8RT–ds10RT). The cumulative X-­ray dose absorbed by the crystal is indicated for each snapshot of the series.

Volume 5| Part 3| May 2018| Pages 283-292
ISSN: 2052-2525