Fig. 5

Crystal structure of PP1α:ASPP2 complex. a Crystal structure of PP1α:ASPP2 complex. ASPP2 is drawn in green cartoons and white transparent surface. PP1 is displayed in pink surface. b The ASPP2 RVxF motif is bound to the PP1 hydrophobic pocket: (PP1α residues I169, L243, F257, R261, V264, M283, L289, C291, F293). The interaction is stabilised by three backbone hydrogen bonds between ASPP2 residues ⁹²³KFN⁹²⁵ and PP1α residues ²⁸⁹LMC²⁹¹. ASPP2^R921 is engaged in a salt bridge with PP1α^D242. c Close-up view of ASPP2 Ankyrin1 domain interaction with PP1. d The PP1α PPII motif binds to ASSP2 SH3 domain. The three core residues PP1α^P318, PP1α^P321 and PP1α^R323 of the PxxPxR motif are engaged in an extensive network of hydrophobic and electrostatic interactions. The side chain of PP1α^R317 forms an additional water-bridged hydrogen bond with the backbone of ASPP2^E1069. We also observed three hydrogen bonds between the PP1α mainchain and the ASPP2 SH3 domain: two between the carbonyls of PP1α^P321/ PP1α^P322 and the side chain of ASPP2^W1097, and one between PP1α^I319 carbonyl and ASPP2^N1112 side chain. e Schematic of PP1 C-tail interaction with ASPP2 SH3 domain. Red shading represents the negatively charged ASPP2 specificity pocket. The last three PP1α lysine residues are shadowed in blue