Fig. 1: Structure of AtMC4 and self-inhibition mechanism.
From: Structural basis for Ca2+-dependent activation of a plant metacaspase
a AtMC4 structure of a catalytically inactive C139A mutant. The three domains are shown as cartoons and are colored differently: p20 domain, marine; linker domain, green; p10 domain, orange. The catalytic dyad (C139A and His86) and a self-processing site (Lys225) are shown as sticks. Disordered region between residues 152 and 211 is shown as a dashed line. b Topological diagram for secondary structures of AtMC4. Coloring is the same as (a). Locations of key residues discussed in the paper are indicated. c Electrostatics surface of the caspase-like core. The electrostatics was calculated by using program APBS42 and plotted at the level of ±4 kT/e. d View of the linker domain attached on the surface of the caspase-like core with its Lys225 inserted in a conserved pocket. The conservation level is mapped to the surface: more conserved surfaces, more magenta; and more variable surfaces, more cyan. e Interactions between the Lys225 region and the caspase-like core. View in e is rotated approximately 180° relative to that of a.
