Bacteriorhodopsin: the mechanism of 2D-array formation and the structure of retinal in the protein.

Bacteriorhodopsin, the light driven proton pump of the extreme halophilic bacterium H. salinarium, is an integral membrane protein (M(r) ca. 26000) which forms 2D arrays in the purple membrane of the bacterium. It is this feature which has permitted the use of electron diffraction methods to resolve...