Taste receptor gene family

The two novel taste receptor gene families,
T1R1 and T1R2, are expressed in distinct subsets
of taste receptor cells. The figure shows an
alignment of the predicted amino acid
sequences of 23 different T2 receptors (T2Rs) of
human (h), rat (r), and mouse (m) origin between
the first (TM1) and the third (TM3) transmembrane
domain. Dark blue indicates identity
in at least half of the aligned sequences;
light blue represents conserved substitutions;
and the remainder are divergent regions. They
reflect the ability to bind many structurally
different ligands. The T2R genes cluster on a few
chromosomes, human chromosomes 5, 7, and
12 and mouse chromosomes 6 and 15.