English: "Structure of full-length AMPK complex with activator: Detailed view of 991 binding in a pocket generated at the interface between the CBM and the kinase domain, and making interactions with a cluster of hydrophobic residues from each domain; Ile-46(Kinase), Phe-90(Kinase), Leu-18(Kinase) and Val-11(Kinase) and Val-81(CBM), Val-113(CBM), Ile-115(CBM) and one of the side-chain carbon atoms (CG) of Thr-106(CBM). These hydrophobic interactions mainly involve ring-1 and ring-2 of the activator. The hydrophobic residues from the kinase (yellow) and CBM (green) are shown as sticks. This view details the polar interactions that contribute to activator binding. Ring-3, and its linkage to ring-2, are involved in a number of polar interactions. Salt-bridges are formed between Asp-88(Kinase) and N2 of ring-2 and Lys-29(Kinase) with the carboxyl group of ring-3. Lys-31(Kinase) interacts with the phosphorylated serine (pSer) at position 108 from the CBM. The CBM contributes an important interaction to drug binding through Arg-83. In addition to making a hydrogen bond with Asn-48(Kinase), it also makes a cation–π stacking interaction with ring-2 of the activator. The cation–π interaction from Arg-83(CBM) with the activator is indicated by hatched lines. Additional potential interactions (where the bond lengths are longer than those expected for a high resolution structure) are indicated by a thin dashed blue line." Figure 3d from B.Xiao et al. "Structural basis of AMPK regulation by small molecule activators" Nature Communications 4 doi:10.1038/ncomms4017 . Image and description adapted under CC-BY 3.0 licence.