Figure 2.

The protease, ADAMTS13. (A) Domain organization of ADAMTS13. From the N-terminus are the metalloprotease domain (MP; red), disintegrin-like domain (Dis; yellow), TSP repeats (1-8; green), cysteine-rich domain (Cys; blue), spacer domain (purple), and CUB domains (orange). Binding sites and function of specific domains are labeled below. (B) Structure of ADAMTS13 N-terminal domains (MDTCS) based on the crystal structure of DTCS and homology modeling of the MP domain. Surface representation is shown. Domains are colored according to panel A. (Insets) Cartoon representation of the location of the high-affinity calcium binding site and coordinating residues (green) in the MP domain, the active site containing 3 His residues (red) and catalytic Glu225 (mauve), the disintegrin-like domain exosite, and spacer domain exosite.