Sequence conservation and structural features that are common within TRP channels

TRP proteins are a large family of cation-selective channels, surpassed in
variety only by voltage-gated potassium channels. Detailed molecular
mechanisms governing how membrane voltage, ligand binding, or temperature
can induce conformational changes promoting the open state in TRP channels
are still a matter of debate. Aiming to unveil distinctive structural
features common to the transmembrane domains within the TRP family, we
performed phylogenetic reconstruction, sequence statistics, and structural
analysis over a large set of TRP channel genes. Here we report an
exceptionally conserved set of residues. This fingerprint is composed of
twelve residues localized at equivalent three-dimensional positions in TRP
channels from the different subtypes. Moreover, these amino acids are
arranged in three groups, connected by a set of aromatics located at the
core of the transmembrane structure. We hypothesize that differences in
the connectivity between these different groups of residues harbors the
apparent differences in coupling strategies used by TRP subgroups.