Figure 5
Chemical delivery through diffusion. (a) From top to bottom, time course of chemical delivery to three crystallization drops containing CDK2 crystals. The pictures are snapshots of the video feedback provided by the software interface of the harvesting robot (see Fig. 3). (1) The crystallization drops as seen through the robot software interface before the start; the selected locations for the aperture and the pin as well as the cutting shape are shown as in Fig. 4. In this case the aperture has a rectangular shape (green square). (2) The aperture has been generated; 50 nl ligand solution has been deposited on the outer side of the film. Occasionally, precipitation of the ligand is observed in the areas proximal to the aperture (red arrows). (3) Mounted and cryocooled samples after liquid removal, as seen from the cryojet camera. (b–g) Detail of six small molecule–CDK2 complex structures obtained from crystals prepared by this method. (b) 2,4,6-Trioxo-1-phenyl-hexahydropyrimidine-5-carboxamide, (c) N-(9H-purin-6-yl)thiophene-2-carboxamide, (d) 6-chloro-7H-purine, (e) 7-hydroxy-4-(morpholinomethyl)chromen-2-one, (f) 6-methoxy-7H-purine and (g) 2-imidazol-1-yl-1H-benzimidazole. The hinge region of CDK2 (Glu81–Leu83) is shown in purple, the gatekeeper residue Phe80 in red and the ligands in green; the 2Fo − Fc OMIT map contoured at 1σ is represented as a blue mesh. Hydrogen-bond interactions are denoted by black dashed lines. Complete data-collection statistics are given in Table 3. |