Abstract
The three-dimensional crystals of the integral membrane protein bacteriorhodopsin have been characterized by X-ray diffraction and freeze-fracture electron microscopy: the needle-like form A crystals belong to space group P 1 (pseudohexagonal) with seven molecules per crystallographic unit cell forming one turn of a non-crystallographic helix. The probable arrangement of the bacteriorhodopsin molecules is derived from freeze-fracture electron micrographs and chromophore orientation. Membrane-like structures are not present. The same helices of bacteriorhodopsin molecules found in crystal form A also make up the cube-like crystal form B. They are now arranged in all three mutually perpendicular directions. These cubes are always highly disordered, since the unit cell length corresponds to 6.7 molecules of the 7-fold helix. Very often, conversion of bacteriorhodopsin from the three-dimensional crystals into filamentous material occurs.
Keywords: crystallization, X-ray, membrane protein, purple membrane, bacteriorhodopsin
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- Blaurock A. E. Bacteriorhodospin: a trans-membrane pump containing alpha-helix. J Mol Biol. 1975 Apr 5;93(2):139–158. doi: 10.1016/0022-2836(75)90124-2. [DOI] [PubMed] [Google Scholar]
- Garavito R. M., Rosenbusch J. P. Three-dimensional crystals of an integral membrane protein: an initial x-ray analysis. J Cell Biol. 1980 Jul;86(1):327–329. doi: 10.1083/jcb.86.1.327. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Henderson R. The structure of the purple membrane from Halobacterium hallobium: analysis of the X-ray diffraction pattern. J Mol Biol. 1975 Apr 5;93(2):123–138. doi: 10.1016/0022-2836(75)90123-0. [DOI] [PubMed] [Google Scholar]
- Henderson R., Unwin P. N. Three-dimensional model of purple membrane obtained by electron microscopy. Nature. 1975 Sep 4;257(5521):28–32. doi: 10.1038/257028a0. [DOI] [PubMed] [Google Scholar]
- Heyn M. P., Cherry R. J., Müller U. Transient and linear dichroism studies on bacteriorhodopsin: determination of the orientation of the 568 nm all-trans retinal chromophore. J Mol Biol. 1977 Dec 15;117(3):607–620. doi: 10.1016/0022-2836(77)90060-2. [DOI] [PubMed] [Google Scholar]
- Korenstein R., Hess B. Immobilization of bacteriorhodopsin and orientation of its transition moment in purple membrane. FEBS Lett. 1978 May 1;89(1):15–20. doi: 10.1016/0014-5793(78)80512-2. [DOI] [PubMed] [Google Scholar]
- Michel H., Oesterhelt D., Henderson R. Orthorhombic two-dimensional crystal form of purple membrane. Proc Natl Acad Sci U S A. 1980 Jan;77(1):338–342. doi: 10.1073/pnas.77.1.338. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Michel H., Oesterhelt D. Three-dimensional crystals of membrane proteins: bacteriorhodopsin. Proc Natl Acad Sci U S A. 1980 Mar;77(3):1283–1285. doi: 10.1073/pnas.77.3.1283. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Michel H. Three-dimensional crystals of a membrane protein complex. The photosynthetic reaction centre from Rhodopseudomonas viridis. J Mol Biol. 1982 Jul 5;158(3):567–572. doi: 10.1016/0022-2836(82)90216-9. [DOI] [PubMed] [Google Scholar]
- Moor H. Recent progress in the freeze-etching technique. Philos Trans R Soc Lond B Biol Sci. 1971 May 27;261(837):121–131. doi: 10.1098/rstb.1971.0042. [DOI] [PubMed] [Google Scholar]
- Oesterhelt D., Stoeckenius W. Isolation of the cell membrane of Halobacterium halobium and its fractionation into red and purple membrane. Methods Enzymol. 1974;31:667–678. doi: 10.1016/0076-6879(74)31072-5. [DOI] [PubMed] [Google Scholar]
- Unwin P. N., Henderson R. Molecular structure determination by electron microscopy of unstained crystalline specimens. J Mol Biol. 1975 May 25;94(3):425–440. doi: 10.1016/0022-2836(75)90212-0. [DOI] [PubMed] [Google Scholar]