1brx: Difference between revisions
New page: left|200px<br /><applet load="1brx" size="450" color="white" frame="true" align="right" spinBox="true" caption="1brx, resolution 2.3Å" /> '''BACTERIORHODOPSIN/LIP... |
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[[Image:1brx.gif|left|200px]]<br /><applet load="1brx" size=" | [[Image:1brx.gif|left|200px]]<br /><applet load="1brx" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1brx, resolution 2.3Å" /> | caption="1brx, resolution 2.3Å" /> | ||
'''BACTERIORHODOPSIN/LIPID COMPLEX'''<br /> | '''BACTERIORHODOPSIN/LIPID COMPLEX'''<br /> | ||
==Overview== | ==Overview== | ||
Photoisomerization of the retinal of bacteriorhodopsin initiates a cyclic | Photoisomerization of the retinal of bacteriorhodopsin initiates a cyclic reaction in which a proton is translocated across the membrane. Studies of this protein promise a better understanding of how ion pumps function. Together with a large amount of spectroscopic and mutational data, the atomic structure of bacteriorhodopsin, determined in the last decade at increasing resolutions, has suggested plausible but often contradictory mechanisms. X-ray diffraction of bacteriorhodopsin crystals grown in cubic lipid phase revealed unexpected two-fold symmetries that indicate merohedral twinning along the crystallographic c axis. The structure, refined to 2.3 angstroms taking this twinning into account, is different from earlier models, including that most recently reported. One of the carboxyl oxygen atoms of the proton acceptor Asp85 is connected to the proton donor, the retinal Schiff base, through a hydrogen-bonded water and forms a second hydrogen bond with another water. The other carboxyl oxygen atom of Asp85 accepts a hydrogen bond from Thr89. This structure forms the active site. The nearby Arg82 is the center of a network of numerous hydrogen-bonded residues and an ordered water molecule. This network defines the pathway of the proton from the buried Schiff base to the extracellular surface. | ||
==About this Structure== | ==About this Structure== | ||
1BRX 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:// | 1BRX 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=1BRX OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Lanyi, J.]] | [[Category: Lanyi, J.]] | ||
[[Category: Luecke, H.]] | [[Category: Luecke, H.]] | ||
[[Category: Richter, H | [[Category: Richter, H T.]] | ||
[[Category: RET]] | [[Category: RET]] | ||
[[Category: haloarchaea]] | [[Category: haloarchaea]] | ||
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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 11:58:26 2008'' | ||
Revision as of 12:58, 21 February 2008
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BACTERIORHODOPSIN/LIPID COMPLEX
OverviewOverview
Photoisomerization of the retinal of bacteriorhodopsin initiates a cyclic reaction in which a proton is translocated across the membrane. Studies of this protein promise a better understanding of how ion pumps function. Together with a large amount of spectroscopic and mutational data, the atomic structure of bacteriorhodopsin, determined in the last decade at increasing resolutions, has suggested plausible but often contradictory mechanisms. X-ray diffraction of bacteriorhodopsin crystals grown in cubic lipid phase revealed unexpected two-fold symmetries that indicate merohedral twinning along the crystallographic c axis. The structure, refined to 2.3 angstroms taking this twinning into account, is different from earlier models, including that most recently reported. One of the carboxyl oxygen atoms of the proton acceptor Asp85 is connected to the proton donor, the retinal Schiff base, through a hydrogen-bonded water and forms a second hydrogen bond with another water. The other carboxyl oxygen atom of Asp85 accepts a hydrogen bond from Thr89. This structure forms the active site. The nearby Arg82 is the center of a network of numerous hydrogen-bonded residues and an ordered water molecule. This network defines the pathway of the proton from the buried Schiff base to the extracellular surface.
About this StructureAbout this Structure
1BRX is a Single protein structure of sequence from Halobacterium salinarum with as ligand. Full crystallographic information is available from OCA.
ReferenceReference
Proton transfer pathways in bacteriorhodopsin at 2.3 angstrom resolution., Luecke H, Richter HT, Lanyi JK, Science. 1998 Jun 19;280(5371):1934-7. PMID:9632391
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