1R84

NMR structure of the 13-cis-15-syn retinal in dark_adapted bacteriorhodopsin

Summary for 1R84

• Entry DOI: 10.2210/pdb1r84/pdb
• Related: 1BRR 1C3W 1R2N
• Descriptor: Bacteriorhodopsin, RETINAL (3 entities in total)
• Functional Keywords: proton pump, membrane protein, retinal protein, photoreceptor, haloarchea, proton transport
• Biological source: Halobacterium salinarum
• Cellular location: Cell membrane; Multi-pass membrane protein: P02945
• Total number of polymer chains: 1
• Total formula weight: 25715.47

Authors

Patzelt, H.,Simon, B.,Ter Laak, A.,Kessler, B.,Kuhne, R.,Schmieder, P.,Oesterhaelt, D.,Oschkinat, H. (deposition date: 2003-10-23, release date: 2003-11-11, Last modification date: 2024-10-30)

Primary citation

Patzelt, H.,Simon, B.,Ter Laak, A.,Kessler, B.,Kuhne, R.,Schmieder, P.,Oesterhaelt, D.,Oschkinat, H.
The structures of the active center in dark-adapted bacteriorhodopsin by solution-state NMR spectroscopy
Proc.Natl.Acad.Sci.USA, 99:9765-9770, 2002

PubMed Abstract: The two forms of bacteriorhodopsin present in the dark-adapted state, containing either all-trans or 13-cis,15-syn retinal, were examined by using solution state NMR, and their structures were determined. Comparison of the all-trans and the 13-cis,15-syn forms shows a shift in position of about 0.25 A within the pocket of the protein. Comparing this to the 13-cis,15-anti chromophore of the catalytic cycle M-intermediate structure, the 13-cis,15-syn form demonstrates a less pronounced up-tilt of the retinal C12[bond]C14 region, while leaving W182 and T178 essentially unchanged. The N[bond]H dipole of the Schiff base orients toward the extracellular side in both forms, however, it reorients toward the intracellular side in the 13-cis,15-anti configuration to form the catalytic M-intermediate. Thus, the change of the N[bond]H dipole is considered primarily responsible for energy storage, conformation changes of the protein, and the deprotonation of the Schiff base. The structural similarity of the all-trans and 13-cis,15-syn forms is taken as strong evidence for the ion dipole dragging model by which proton (hydroxide ion) translocation follows the change of the dipole.

PubMed: 12119389
DOI: 10.1073/pnas.132253899

Experimental method

SOLUTION NMR