Shown are 3-dimensional models of metalloprotease, Tsp1-5, and Tsp1-8 domains of ADAMTS13. (A) Metalloprotease domain. The side chains of Arg193 and Arg268 are shown in blue with residue numbers. The active site zinc ion coordinated by His224, His228, and His234 is also shown (green). The mutations of H96D, R102C, T196I, L232Q, and S263C reported by Levy et al¹²  and Schneppenheim et al³¹  are present in the metalloprotease domain. The side chains of His96, Arg102, Thr196, Leu232, and Ser263 are also shown in blue. (B) Tsp1-5 domain. The side chains of Cys908 and Cys951 are shown in red with residue numbers. (C) Tsp1-8 domain. The side chain of Arg1123 is shown in red with residue number.