Fig. 4.

The difference in sequences of Gαi subunits and efficiency of energy transfer. a Multiple protein sequence alignment of human Gαi subunits encompassing residues of N-terminal fragment. The residues are colored to indicate their physicochemical properties: red—negatively charged amino acids, blue—residues with a positive charge, magenta indicates hydrogen bonding, and yellow shows hydrophobic aliphatic residues. In the consensus line, the positions in which there are differences in the sequence shown in yellow. Modified from gpcrdb.org (83). b A plot of calculated FRET efficiency percentage E derived from τ₁; error bars represent standard errors