NMR structural study of the intracellular loop 3 of the serotonin 5-HT1A receptor and its interaction with calmodulin

► The intracellular Loop 3 (ICL3) of the Serotonin 5-HT2A receptor was purified. ► Backbone resonance assignment showed the presence of an alpha-helical structure. ► A new calmodulin binding site was identified. ► Both N and C terminus of calmodulin are affected by its interaction with ICL3.