(B) Comparison of the ELM domain hydrophobic cores. The ELM1 core contains the UNL, modelled here as homoserine shown in spheres, occupying a ∼442 Å3 cavity highlighted with mesh. The ELM2 core includes three tryptophans in close proximity (W367, W391, W395 in orange). Hydrophobic residues in the LM/EF hand pair interfaces are also shown in sticks. LM, ligand mimic; UNL, unidentified ligand. 