1f4z: Difference between revisions

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Revision as of 12:04, 20 March 2008

File:1f4z.jpg

, resolution 1.80Å

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BACTERIORHODOPSIN-M PHOTOINTERMEDIATE STATE OF THE E204Q MUTANT AT 1.8 ANGSTROM RESOLUTION

OverviewOverview

In order to understand how isomerization of the retinal drives unidirectional transmembrane ion transport in bacteriorhodopsin, we determined the atomic structures of the BR state and M photointermediate of the E204Q mutant, to 1.7 and 1.8 A resolution, respectively. Comparison of this M, in which proton release to the extracellular surface is blocked, with the previously determined M in the D96N mutant indicates that the changes in the extracellular region are initiated by changes in the electrostatic interactions of the retinal Schiff base with Asp85 and Asp212, but those on the cytoplasmic side originate from steric conflict of the 13-methyl retinal group with Trp182 and distortion of the pi-bulge of helix G. The structural changes suggest that protonation of Asp85 initiates a cascade of atomic displacements in the extracellular region that cause release of a proton to the surface. The progressive relaxation of the strained 13-cis retinal chain with deprotonated Schiff base, in turn, initiates atomic displacements in the cytoplasmic region that cause the intercalation of a hydrogen-bonded water molecule between Thr46 and Asp96. This accounts for the lowering of the pK(a) of Asp96, which then reprotonates the Schiff base via a newly formed chain of water molecules that is extending toward the Schiff base.

About this StructureAbout this Structure

1F4Z is a Single protein structure of sequence from Halobacterium salinarum. Full crystallographic information is available from OCA.

ReferenceReference

Coupling photoisomerization of retinal to directional transport in bacteriorhodopsin., Luecke H, Schobert B, Cartailler JP, Richter HT, Rosengarth A, Needleman R, Lanyi JK, J Mol Biol. 2000 Jul 28;300(5):1237-55. PMID:10903866

Page seeded by OCA on Thu Mar 20 11:04:28 2008

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA

@@ Line 1: / Line 1: @@
-[[Image:1f4z.jpg|left|200px]]<br /><applet load="1f4z" size="350" color="white" frame="true" align="right" spinBox="true"
+[[Image:1f4z.jpg|left|200px]]
-caption="1f4z, resolution 1.80&Aring;" />
-'''BACTERIORHODOPSIN-M PHOTOINTERMEDIATE STATE OF THE E204Q MUTANT AT 1.8 ANGSTROM RESOLUTION'''<br />
+ {{Structure
+|PDB= 1f4z |SIZE=350|CAPTION= <scene name='initialview01'>1f4z</scene>, resolution 1.80&Aring;
+|SITE=
+|LIGAND= <scene name='pdbligand=LI1:1-[2,6,10.14-TETRAMETHYL-HEXADECAN-16-YL]-2-[2,10,14-TRIMETHYLHEXADECAN-16-YL]GLYCEROL'>LI1</scene>, <scene name='pdbligand=SQU:2,10,23-TRIMETHYL-TETRACOSANE'>SQU</scene> and <scene name='pdbligand=RET:RETINAL'>RET</scene>
+|ACTIVITY=
+|GENE=
+}}
+'''BACTERIORHODOPSIN-M PHOTOINTERMEDIATE STATE OF THE E204Q MUTANT AT 1.8 ANGSTROM RESOLUTION'''
 ==Overview==
@@ Line 7: / Line 16: @@
 ==About this Structure==
-F4Z 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=LI1:'>LI1</scene>, <scene name='pdbligand=SQU:'>SQU</scene> and <scene name='pdbligand=RET:'>RET</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1F4Z OCA].
+F4Z is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Halobacterium_salinarum Halobacterium salinarum]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1F4Z OCA].
 ==Reference==
-Coupling photoisomerization of retinal to directional transport in bacteriorhodopsin., Luecke H, Schobert B, Cartailler JP, Richter HT, Rosengarth A, Needleman R, Lanyi JK, J Mol Biol. 2000 Jul 28;300(5):1237-55. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=10903866 10903866]
+Coupling photoisomerization of retinal to directional transport in bacteriorhodopsin., Luecke H, Schobert B, Cartailler JP, Richter HT, Rosengarth A, Needleman R, Lanyi JK, J Mol Biol. 2000 Jul 28;300(5):1237-55. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/10903866 10903866]
 [[Category: Halobacterium salinarum]]
 [[Category: Single protein]]
@@ Line 28: / Line 37: @@
 [[Category: ion pump]]
 [[Category: ion transport]]
-[[Category: lipids]]
+[[Category: lipid]]
 [[Category: membrane protein]]
 [[Category: merohedral twinning]]
@@ Line 35: / Line 44: @@
 [[Category: retinal protein]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:34:58 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 11:04:28 2008''