Conserved sequence motifs in the OR family. Sequence motifs based on analysis of the multiple sequence alignment of the full-length hOR repertoire are represented as 'sequence logo' [43,44]. The height of each amino-acid symbol in a given position is proportional to its frequency of occurrence. The height of the sequence information part is computed as the relative entropy between the observed fractions of a given amino-acid symbol and the respective a priori probabilities (assumed to be 0.05 for each amino acid). Locations of predicted transmembrane segments (TM1-7) as well as intracellular loops (IC1-3) and extracellular loops (EC1-3) are shown. TM boundaries are based on the predictions done using the neural network algorithm implemented with the PHDhtm and PHD topology programs [42,77,78]. The alignment was edited to adjust for OR length heterogeneity before sequence logo generation as described in Materials and methods. This figure is available as an additional data file in PDF format.