Figure 4.
Cartoon/surface views of the thrombin-3L, thrombin-3G, and thrombin-3Leu interfaces
(A–C) Thrombin-3L (A), thrombin-3G (B), and thrombin-3Leu (C). In the panels, the 2Fo–Fc electron density maps of the modified nucleobases contoured at the 1.0 σ level. In all complexes, the modified thymine base stacks on Tyr76 in the B-region of thrombin exosite I. (D) As a comparison, the interface between thrombin and the parent TBA (PDB: 4DII) and the stacking interaction of its Thy12 and Tyr76 are also shown. Thrombin is colored in green, and 3L, 3G, 3Leu, and TBA are colored in yellow, cyan, orange, and dark red, respectively.