1kg8: Difference between revisions
New page: left|200px<br /><applet load="1kg8" size="450" color="white" frame="true" align="right" spinBox="true" caption="1kg8, resolution 2.0Å" /> '''X-ray structure of an... |
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[[Image:1kg8.jpg|left|200px]]<br /><applet load="1kg8" size=" | [[Image:1kg8.jpg|left|200px]]<br /><applet load="1kg8" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1kg8, resolution 2.0Å" /> | caption="1kg8, resolution 2.0Å" /> | ||
'''X-ray structure of an early-M intermediate of bacteriorhodopsin'''<br /> | '''X-ray structure of an early-M intermediate of bacteriorhodopsin'''<br /> | ||
==Overview== | ==Overview== | ||
The structure of an early M-intermediate of the wild-type | The structure of an early M-intermediate of the wild-type bacteriorhodopsin photocycle formed by actinic illumination at 230 K has been determined by x-ray crystallography to a resolution of 2.0 A. Three-dimensional crystals were trapped by illuminating with actinic light at 230 K, followed by quenching in liquid nitrogen. Amide I, amide II, and other infrared absorption bands, recorded from single bacteriorhodopsin crystals, confirm that the M-substate formed represents a structure that occurs early after deprotonation of the Schiff base. Rotation about the retinal C13-C14 double bond appears to be complete, but a relatively large torsion angle of 26 degrees is still seen for the C14-C15 bond. The intramolecular stress associated with the isomerization of retinal and the subsequent deprotonation of the Schiff base generates numerous small but experimentally measurable structural changes within the protein. Many of the residues that are displaced during the formation of the late M (M(N)) substate formed by three-dimensional crystals of the D96N mutant (Luecke et al., 1999b) are positioned, in early M, between their resting-state locations and the ones which they will adopt at the end of the M phase. The relatively small magnitude of atomic displacements observed in this intermediate, and the well-defined positions adopted by nearly all of the atoms in the structure, may make the formation of this structure favorable to model (simulate) by molecular dynamics. | ||
==About this Structure== | ==About this Structure== | ||
1KG8 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 and LI1 as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | 1KG8 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> and <scene name='pdbligand=LI1:'>LI1</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KG8 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Halobacterium salinarum]] | [[Category: Halobacterium salinarum]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Betancourt, F | [[Category: Betancourt, F M.]] | ||
[[Category: Burkard, F | [[Category: Burkard, F T.]] | ||
[[Category: Downing, K | [[Category: Downing, K H.]] | ||
[[Category: Facciotti, M | [[Category: Facciotti, M T.]] | ||
[[Category: Glaeser, R | [[Category: Glaeser, R M.]] | ||
[[Category: McDermott, G.]] | [[Category: McDermott, G.]] | ||
[[Category: Rose, R | [[Category: Rose, R B.]] | ||
[[Category: Rouhani, S.]] | [[Category: Rouhani, S.]] | ||
[[Category: LI1]] | [[Category: LI1]] | ||
| Line 27: | Line 27: | ||
[[Category: m-state]] | [[Category: m-state]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:33:53 2008'' | ||
Revision as of 14:33, 21 February 2008
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X-ray structure of an early-M intermediate of bacteriorhodopsin
OverviewOverview
The structure of an early M-intermediate of the wild-type bacteriorhodopsin photocycle formed by actinic illumination at 230 K has been determined by x-ray crystallography to a resolution of 2.0 A. Three-dimensional crystals were trapped by illuminating with actinic light at 230 K, followed by quenching in liquid nitrogen. Amide I, amide II, and other infrared absorption bands, recorded from single bacteriorhodopsin crystals, confirm that the M-substate formed represents a structure that occurs early after deprotonation of the Schiff base. Rotation about the retinal C13-C14 double bond appears to be complete, but a relatively large torsion angle of 26 degrees is still seen for the C14-C15 bond. The intramolecular stress associated with the isomerization of retinal and the subsequent deprotonation of the Schiff base generates numerous small but experimentally measurable structural changes within the protein. Many of the residues that are displaced during the formation of the late M (M(N)) substate formed by three-dimensional crystals of the D96N mutant (Luecke et al., 1999b) are positioned, in early M, between their resting-state locations and the ones which they will adopt at the end of the M phase. The relatively small magnitude of atomic displacements observed in this intermediate, and the well-defined positions adopted by nearly all of the atoms in the structure, may make the formation of this structure favorable to model (simulate) by molecular dynamics.
About this StructureAbout this Structure
1KG8 is a Single protein structure of sequence from Halobacterium salinarum with and as ligands. Full crystallographic information is available from OCA.
ReferenceReference
Structure of an early intermediate in the M-state phase of the bacteriorhodopsin photocycle., Facciotti MT, Rouhani S, Burkard FT, Betancourt FM, Downing KH, Rose RB, McDermott G, Glaeser RM, Biophys J. 2001 Dec;81(6):3442-55. PMID:11721006
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