1BRR

X-RAY STRUCTURE OF THE BACTERIORHODOPSIN TRIMER/LIPID COMPLEX

Summary for 1BRR

• Entry DOI: 10.2210/pdb1brr/pdb
• Descriptor: PROTEIN (BACTERIORHODOPSIN), 3-O-sulfo-beta-D-galactopyranose-(1-6)-alpha-D-mannopyranose-(1-2)-alpha-D-glucopyranose, RETINAL, ... (7 entities in total)
• Functional Keywords: proton pump, membrane protein, retinal protein, lipids, photoreceptor, haloarchaea, proton transport
• Biological source: Halobacterium salinarum
• Total number of polymer chains: 3
• Total formula weight: 85799.44

Authors

Essen, L.-O.,Siegert, R.,Oesterhelt, D. (deposition date: 1998-07-28, release date: 1998-09-30, Last modification date: 2024-11-20)

Primary citation

Essen, L.,Siegert, R.,Lehmann, W.D.,Oesterhelt, D.
Lipid patches in membrane protein oligomers: crystal structure of the bacteriorhodopsin-lipid complex
Proc.Natl.Acad.Sci.USA, 95:11673-11678, 1998

PubMed Abstract: Heterogenous nucleation on small molecule crystals causes a monoclinic crystal form of bacteriorhodopsin (BR) in which trimers of this membrane protein pack differently than in native purple membranes. Analysis of single crystals by nano-electrospray ionization-mass spectrometry demonstrated a preservation of the purple membrane lipid composition in these BR crystals. The 2.9-A x-ray structure shows a lipid-mediated stabilization of BR trimers where the glycolipid S-TGA-1 binds into the central compartment of BR trimers. The BR trimer/lipid complex provides an example of local membrane thinning as the lipid head-group boundary of the central lipid patch is shifted by 5 A toward the membrane center. Nonbiased electron density maps reveal structural differences to previously reported BR structures, especially for the cytosolic EF loop and the proton exit pathway. The terminal proton release complex now comprises an E194-E204 dyad as a diffuse proton buffer.

PubMed: 9751724
DOI: 10.1073/pnas.95.20.11673

Experimental method

X-RAY DIFFRACTION (2.9 Å)