Fig. 2: SHOC2–MRAS–PP1Cα interfaces include polar contacts and coordinated solvent.

a, Cartoon view of the complex of SHOC2 (pale blue), MRAS (grey) and PP1Cα (maroon), illustrating interactions mediated by the concave surface of SHOC2. SWI and SWII of MRAS are highlighted in pink and green, respectively; GppNHp is rendered in ball and stick; and Mg²⁺ is represented as a green sphere. The phosphate bound to the active site of PP1C is represented in red, and the Mn²⁺ metals are indicated as orange spheres. This colour scheme is maintained throughout all of the figures. b, Cooperative interface of SHOC2, PP1Cα and MRAS mediated by SWI (pale green) and SWII (pink) of MRAS. c, SHOC2 uses its β-sheet surface and descending loops from multiple LRRs to recruit MRAS while binding to PP1Cα through the ascending loops of numerous LRRs. One representative LRR (orange) is shown. MRAS and PP1Cα are shown in surface representation. d, Direct and water-mediated interactions at the cooperative interface highlighting MRAS SWI interactions with Arg188 of PP1Cα helix G. The indicated side chains are colour coded by subunit with representative water molecules indicated by red spheres and bonding networks highlighted by dashed lines. An MRAS-bound magnesium ion is shown as a green sphere. e, Direct and water-mediated interactions at the cooperative interface as in d, but highlighting MRAS SWI and SWII interactions with SHOC2.