[Possible determination of the structural organization of bacterial and animal rhodopsins by the hydrophobicity of amino acid residues].

From a comparative analysis of the distribution of hydrophobicity in bacterial and animal (bovine) rhodopsins, the following peculiarities in the structure of these proteins have been assumed: 1) each of these proteins has 5 hydrophobic regions of equal length (20-28 residues) able to be arranged across the membrane and one region of doubled length. 2) The alpha-helix of the doubled-length regions (residues N 178-225 for bacterial rhodopsin and N 75-132 for the animal one) is characterized by pronounced amphipaticity and is capable of a retinal dependent movement in the membrane. The model of animal rhodopsin was suggested to have 13 phenylalanine residues forming a chain which "connects" 6 transmembrane segments and runs from one surface of the membrane to the opposite one.