1XJI

Bacteriorhodopsin crystallized in bicelles at room temperature

Summary for 1XJI

• Entry DOI: 10.2210/pdb1xji/pdb
• Descriptor: Bacteriorhodopsin, RETINAL, DODECANE, ... (8 entities in total)
• Functional Keywords: membrane protein bacteriorhodopsin, membrane protein
• Biological source: Halobacterium salinarum
• Cellular location: Cell membrane; Multi-pass membrane protein: P02945
• Total number of polymer chains: 1
• Total formula weight: 29150.70

Authors

Faham, S.,Boulting, G.L.,Massey, E.A.,Yohannan, S.,Yang, D.,Bowie, J.U. (deposition date: 2004-09-23, release date: 2005-04-19, Last modification date: 2024-10-30)

Primary citation

Faham, S.,Boulting, G.L.,Massey, E.A.,Yohannan, S.,Yang, D.,Bowie, J.U.
Crystallization of bacteriorhodopsin from bicelle formulations at room temperature
Protein Sci., 14:836-840, 2005

PubMed Abstract: We showed previously that high-quality crystals of bacteriorhodopsin (bR) from Halobacterium salinarum can be obtained from bicelle-forming DMPC/CHAPSO mixtures at 37 degrees C. As many membrane proteins are not sufficiently stable for crystallization at this high temperature, we tested whether the bicelle method could be applied at a lower temperature. Here we show that bR can be crystallized at room temperature using two different bicelle-forming compositions: DMPC/CHAPSO and DTPC/CHAPSO. The DTPC/CHAPSO crystals grown at room temperature are essentially identical to the previous, twinned crystals: space group P21 with unit cell dimensions of a = 44.7 A, b = 108.7 A, c = 55.8 A, beta = 113.6 degrees . The room-temperature DMPC/CHAPSO crystals are untwinned, however, and belong to space group C222(1) with the following unit cell dimensions: a = 44.7 A, b = 102.5 A, c = 128.2 A. The bR protein packs into almost identical layers in the two crystal forms, but the layers stack differently. The new untwinned crystal form yielded clear density for a previously unresolved CHAPSO molecule inserted between protein subunits within the layers. The ability to grow crystals at room temperature significantly expands the applicability of bicelle crystallization.

PubMed: 15689517
DOI: 10.1110/ps.041167605

Experimental method

X-RAY DIFFRACTION (2.2 Å)