Olfactory receptor protein

The cloning of a large gene family from the olfactory
epithelium of the rat (Buck and Axel,
1991), demonstrated that a receptor protein
contains seven transmembrane regions and
shows marked structural homology with
rhodopsin and !-adrenergic receptors. Unlike
rhodopsin, the olfactory receptor proteins contain
variable amino acids, especially in the
fourth and fifth transmembrane domains. The
third intracellular loop between transmembrane
domains V and VI is relatively short (17
Genetics and Medicine
amino acids), in contrast to other receptor proteins.
It is assumed that contact with the
various G proteins takes place here