1r2n
From Proteopedia
(New page: 200px<br /><applet load="1r2n" size="450" color="white" frame="true" align="right" spinBox="true" caption="1r2n" /> '''NMR structure of the all-trans retinal in da...) |
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- | [[Image:1r2n.gif|left|200px]]<br /><applet load="1r2n" size=" | + | [[Image:1r2n.gif|left|200px]]<br /><applet load="1r2n" size="350" color="white" frame="true" align="right" spinBox="true" |
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'''NMR structure of the all-trans retinal in dark-adapted Bacteriorhodopsin'''<br /> | '''NMR structure of the all-trans retinal in dark-adapted Bacteriorhodopsin'''<br /> | ||
==Overview== | ==Overview== | ||
- | The two forms of bacteriorhodopsin present in the dark-adapted state, containing either all-trans or 13-cis,15-syn retinal, were examined by | + | 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. |
==About this Structure== | ==About this Structure== | ||
- | 1R2N is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Halobacterium_salinarum Halobacterium salinarum] with RET as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1R2N is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Halobacterium_salinarum Halobacterium salinarum] with <scene name='pdbligand=RET:'>RET</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1R2N OCA]. |
==Reference== | ==Reference== | ||
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[[Category: retinal protein]] | [[Category: retinal protein]] | ||
- | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:46:25 2008'' |
Revision as of 12:46, 21 February 2008
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NMR structure of the all-trans retinal in dark-adapted Bacteriorhodopsin
Overview
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.
About this Structure
1R2N is a Single protein structure of sequence from Halobacterium salinarum with as ligand. Full crystallographic information is available from OCA.
Reference
The structures of the active center in dark-adapted bacteriorhodopsin by solution-state NMR spectroscopy., Patzelt H, Simon B, terLaak A, Kessler B, Kuhne R, Schmieder P, Oesterhelt D, Oschkinat H, Proc Natl Acad Sci U S A. 2002 Jul 23;99(15):9765-70. Epub 2002 Jul 15. PMID:12119389
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