1at9
From Proteopedia
(New page: 200px<br /><applet load="1at9" size="450" color="white" frame="true" align="right" spinBox="true" caption="1at9, resolution 3.0Å" /> '''STRUCTURE OF BACTERIO...) |
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| - | [[Image:1at9.gif|left|200px]]<br /><applet load="1at9" size=" | + | [[Image:1at9.gif|left|200px]]<br /><applet load="1at9" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1at9, resolution 3.0Å" /> | caption="1at9, resolution 3.0Å" /> | ||
'''STRUCTURE OF BACTERIORHODOPSIN AT 3.0 ANGSTROM DETERMINED BY ELECTRON CRYSTALLOGRAPHY'''<br /> | '''STRUCTURE OF BACTERIORHODOPSIN AT 3.0 ANGSTROM DETERMINED BY ELECTRON CRYSTALLOGRAPHY'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Bacteriorhodopsin is a transmembrane protein that uses light energy, absorbed by its chromophore retinal, to pump protons from the cytoplasm of | + | Bacteriorhodopsin is a transmembrane protein that uses light energy, absorbed by its chromophore retinal, to pump protons from the cytoplasm of bacteria such as Halobacterium salinarium into the extracellular space. It is made up of seven alpha-helices, and in the bacterium forms natural, two-dimensional crystals called purple membranes. We have analysed these crystals by electron cryo-microscopy to obtain images of bacteriorhodopsin at 3.0 A resolution. The structure covers nearly all 248 amino acids, including loops outside the membrane, and reveals the distribution of charged residues on both sides of the membrane surface. In addition, analysis of the electron-potential map produced by this method allows the determination of the charge status of these residues. On the extracellular side, four glutamate residues surround the entrance to the proton channel, whereas on the cytoplasmic side, four aspartic acids occur in a plane at the boundary of the hydrophobic-hydrophilic interface. The negative charges produced by these aspartate residues is encircled by areas of positive charge that may facilitate accumulation and lateral movement of protons on this surface. |
==About this Structure== | ==About this Structure== | ||
| - | 1AT9 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:// | + | 1AT9 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=1AT9 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Miyazawa, A.]] | [[Category: Miyazawa, A.]] | ||
[[Category: Murata, K.]] | [[Category: Murata, K.]] | ||
| - | [[Category: Vassylyev, D | + | [[Category: Vassylyev, D G.]] |
[[Category: RET]] | [[Category: RET]] | ||
[[Category: electron microscopy]] | [[Category: electron microscopy]] | ||
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[[Category: two-dimensional crystal]] | [[Category: two-dimensional crystal]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:48:03 2008'' |
Revision as of 09:48, 21 February 2008
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STRUCTURE OF BACTERIORHODOPSIN AT 3.0 ANGSTROM DETERMINED BY ELECTRON CRYSTALLOGRAPHY
Overview
Bacteriorhodopsin is a transmembrane protein that uses light energy, absorbed by its chromophore retinal, to pump protons from the cytoplasm of bacteria such as Halobacterium salinarium into the extracellular space. It is made up of seven alpha-helices, and in the bacterium forms natural, two-dimensional crystals called purple membranes. We have analysed these crystals by electron cryo-microscopy to obtain images of bacteriorhodopsin at 3.0 A resolution. The structure covers nearly all 248 amino acids, including loops outside the membrane, and reveals the distribution of charged residues on both sides of the membrane surface. In addition, analysis of the electron-potential map produced by this method allows the determination of the charge status of these residues. On the extracellular side, four glutamate residues surround the entrance to the proton channel, whereas on the cytoplasmic side, four aspartic acids occur in a plane at the boundary of the hydrophobic-hydrophilic interface. The negative charges produced by these aspartate residues is encircled by areas of positive charge that may facilitate accumulation and lateral movement of protons on this surface.
About this Structure
1AT9 is a Single protein structure of sequence from Halobacterium salinarum with as ligand. Full crystallographic information is available from OCA.
Reference
Surface of bacteriorhodopsin revealed by high-resolution electron crystallography., Kimura Y, Vassylyev DG, Miyazawa A, Kidera A, Matsushima M, Mitsuoka K, Murata K, Hirai T, Fujiyoshi Y, Nature. 1997 Sep 11;389(6647):206-11. PMID:9296502
Page seeded by OCA on Thu Feb 21 11:48:03 2008
Categories: Halobacterium salinarum | Single protein | Fujiyoshi, Y. | Hirai, T. | Kidera, A. | Kimura, Y. | Matsushima, M. | Mitsuoka, K. | Miyazawa, A. | Murata, K. | Vassylyev, D G. | RET | Electron microscopy | Membrane protein | Photoreceptor | Proton pump | Retinal protein | Two-dimensional crystal
