The sweet taste receptor is a heterodimer of T1R2 and T1R3 subunits that bind sweet compounds at different sites.

Human sweet taste receptors consist of T1R2 and T1R3 subunits forming a heterodimer. Natural sugars and artificial sweeteners bind to different domains within these subunits. For instance, sucrose and sucralose bind to extracellular venus-flytrap domains on both subunits, whereas sweeteners like aspartame bind only to T1R2. This diversity enables receptors to detect a wide range of sweet molecules, explaining the varied sweetness profiles of artificial sweeteners.