FIGURE 3.

Crystal structure of human FD in complex with AFD. A, the structure of one of the two FD-AFD complexes in the asymmetric unit is shown as a ribbon diagram. FD is shown in white, and the AFD LC and HC are shown in yellow and orange, respectively. VD, variable domain; CD, constant domain. B, close-up of the FD catalytic triad His-57, Asp-102, and Ser-195. The structures of human FD (green) and cynomolgus FD (white) are overlaid. His-57 is shown in three different positions as found in different structures. Ser-215 of the self-inhibitory loop is also indicated.