Figure 5.

Structures useful for the study of MT₁ receptor structure–function relationships. MT₁*‐MLT (A) was derived from active forms of rhodopsin, β₂‐adrenoceptor and A_2A adenosine receptors (unpublished data, N.R.). Docking of melatonin (MLT) in the solvent‐accessible cavity was achieved by energy relaxation by 300‐ns molecular dynamics simulations. The structure of the MT₁*‐MLT‐Giα₃ complex could be modelled on the basis of the sequence homology with the β2‐adrenoceptor‐Gα_s structure (Rasmussen et al., 2011b) and the homology between Gα_s and Giα₃ (Soundararajan et al., 2008) (B) whereas the structure of the MT₁*‐MLT‐arrestin complex could be modelled based on the crystallized rhodopsin‐arrestin complex (Kang et al., 2015) (C).