Figure 1
From: Structure of prothrombin in the closed form reveals new details on the mechanism of activation
Engineering and overall structure of the closed conformation of prothrombin. (a) Color-coded domain architecture of prothrombin displaying the location of the engineered disulfide bond linking kringle-1 with the protease domain. Natural disulfide bonds are shown as black lines and positioning of the cleavage sites are indicated. (b) Limited proteolysis of protWT (lanes 0–4) and proTCC (lanes 5–8) by fXa (100 nM) in the absence (−) and presence (+) of reducing agent. Shown are times 0 (lanes 1–2 and 5–6, 6 μg) and 120 min (lanes 3–4 and 7–8, 2.5 μg). The MW marker is shown in lane 9 (62,49,38,28,17 kDa). The full-length gel is presented in Supplementary Fig. 5. (c) Overall structure of proTCC solved at 4.1 Å resolution colored as in a shown as cartoon (left) or surface (right) after 180° rotation. The key residue Tyr93 sits at the interface between kringle-1 and the protease domain. fXa cleavage sites Arg155, Arg271 and Arg320 are shown as spheres (magenta). The catalytic triad His363, Asp419 and Ser525 is shown as spheres (cyan). Zoom-in view of the artificial disulfide bond Cys101-Cys470. The electron density 2Fo-Fc map is countered at 1.5σ.
