Fig. 2: Interdomain interactions and structural features of nonenzymatic domains.

a CalA3 atomic model is shown in gray surface. Bordered with dashed lines: contacts between ψKR/KR and LD-AT domains are shown in orange and purple, respectively; the interfaces contributed by LD or linker are colored green; two different locations of DD are shown in yellow. b ψKR/KR and LD-AT domains are split up from the whole structure, and rotated to the front views to highlight the interaction pattern. c Two distinct docking ___domain conformations. The nearly horizontal conformation of DD contacts with ATʹ ___domain through two residues (shown as sticks). The rotational degree of DD and the residues that mediate this swing are labeled. d C1 type of ψKR/KR ___domain structure. e Two subdomain-arranged AT structure. f Two hotdog fold-adopted DH ___domain structure. These three inactive domains are both shown in ribbon representations, and the close-up views of active site regions are shown as mesh in (e), (f), and (d), respectively. The loss of canonical active site residues (shown as sticks) and the alteration of necessary structural elements are highlighted in green color. The cavities are shown in gray transparent surfaces. See also Supplementary Figs. 12–14 for more details.