Amino acid sequence of bacteriorhodopsin.

The complete primary structure of the purple membrane protein bacteriorhodopsin, which contains 248 amino acid residues, has been determined. Methods used for separation of the hydrophobic fragments included gel permeation and reverse-phase high-pressure liquid chromatography in organic solvents. The amino acid sequence was determined by a combination of automatic Edman degradation and mass spectrometric methods. The total sequence was derived by ordering of the CNBr fragments on the basis of methionine-containing peptides identified by gas chromatographic mass spectrometry and by analysis of N-bromosuccinimide fragments containing overlaps between CNBr fragments. The present sequence differs from that recently reported by Ovchinnikov and coworkers with respect to an additional tryptophan (position 138) and several amino acid assignments.