Schematic diagram of the Ron receptor. A) Domains of the Ron receptor. P loop (orange) and αC helix (blue) in the kinase N lobe and activation loop (yellow) in the C lobe are denoted by different colors. Critical tyrosines in the activation loop (P-2Y: Y1238, 1239) and c-terminal tail (P-Y: Y1353,1360) are indicated. B) The juxtamembrane domain of Ron is divided into four sequential regions: JM-A (residue 982–1008), the region at the N terminus; JM-B (1009–1035), the region corresponding to the sequence deleted in mRon; JM-C (1036–1047), the region with an acidic patch of residues; and JM-D (1048–1081), the region at the c-terminus of the juxtamembrane domain. Residues discussed herein are indicated.