Class A (Rhodopsin-like receptors)

This is the biggest group, making up about 85% of all G-protein coupled receptors (GPCRs). It has receptors that respond to hormones, neurotransmitters, and Sensory signals such as light and smell. The group is divided into smaller categories, including aminergic, peptide, protein, and sensory receptors.
Basith et al. 2018 Front Pharmacol 9: 128
Do et al. 2022 Proteins 90(2): 601-614