This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.

Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.


1x0i

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
Line 1: Line 1:
-
[[Image:1x0i.gif|left|200px]]
+
{{Seed}}
 +
[[Image:1x0i.png|left|200px]]
<!--
<!--
Line 9: Line 10:
{{STRUCTURE_1x0i| PDB=1x0i | SCENE= }}
{{STRUCTURE_1x0i| PDB=1x0i | SCENE= }}
-
'''Crystal Structure of the Acid Blue Form of Bacteriorhodopsin'''
+
===Crystal Structure of the Acid Blue Form of Bacteriorhodopsin===
-
==Overview==
+
<!--
-
Bacteriorhodopsin, a light-driven proton pump found in the purple membrane of Halobacterium salinarum, exhibits purple at neutral pH but its color is sensitive to pH. Here, structures are reported for an acid blue form and an alkaline purple form of wild-type bacteriorhodopsin. When the P622 crystal prepared at pH 5.2 was acidified with sulfuric acid, its color turned to blue with a pKa of 3.5 and a Hill coefficient of 2. Diffraction data at pH 2-5 indicated that the purple-to-blue transition accompanies a large structural change in the proton release channel; i.e. the extracellular half of helix C moves towards helix G, narrowing the proton release channel and expelling a water molecule from a micro-cavity in the vicinity of the retinal Schiff base. In this respect, the acid-induced structural change resembles the structural change observed upon formation of the M intermediate. But, the acid blue form contains a sulfate ion in a site(s) near Arg82 that is created by re-orientations of the carboxyl groups of Glu194 and Glu204, residues comprising the proton release complex. This result suggests that proton uptake by the proton release complex evokes the anion binding, which in turn induces protonation of Asp85, a key residue regulating the absorption spectrum of the chromophore. Interestingly, a pronounced structural change in the proton release complex was also observed at high pH; i.e. re-orientation of Glu194 towards Tyr83 was found to take place at around pH 10. This alkaline transition is suggested to be accompanied by proton release from the proton release complex and responsible for rapid formation of the M intermediate at high pH.
+
The line below this paragraph, {{ABSTRACT_PUBMED_16023672}}, adds the Publication Abstract to the page
 +
(as it appears on PubMed at http://www.pubmed.gov), where 16023672 is the PubMed ID number.
 +
-->
 +
{{ABSTRACT_PUBMED_16023672}}
==About this Structure==
==About this Structure==
Line 27: Line 31:
[[Category: 7 transmembrane helice]]
[[Category: 7 transmembrane helice]]
[[Category: Membrane protein]]
[[Category: Membrane protein]]
-
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 14:22:45 2008''
+
 
 +
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Jul 10 12:37:49 2008''

Revision as of 09:37, 10 July 2008

Image:1x0i.png

Template:STRUCTURE 1x0i

Crystal Structure of the Acid Blue Form of Bacteriorhodopsin

Template:ABSTRACT PUBMED 16023672

About this Structure

1X0I is a Single protein structure of sequence from Halobacterium salinarum. Full crystallographic information is available from OCA.

Reference

Crystal structures of acid blue and alkaline purple forms of bacteriorhodopsin., Okumura H, Murakami M, Kouyama T, J Mol Biol. 2005 Aug 19;351(3):481-95. PMID:16023672

Page seeded by OCA on Thu Jul 10 12:37:49 2008

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1x0i"
Personal tools