Sandbox Reserved 496

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
Line 4: Line 4:
-
'''Cholix Toxin''' named also CT, is a protein toxin that uses ADP-ribosyltransferases to modify target proteins in human cells. The mono-ADP-ribosyltransferase toxins are bacterial virulence factors that are believed to be a factor in many disease states in animals plants as well even humans. For a list of various and other similar toxins see [[Toxins]].
+
== '''Bifunctional Carbon Monoxide Dehydrogenase/Acetyl-CoA Synthase (CODH/ACS)''' ==
 +
<Structure load='1mjg' size='500' frame='true' align='right' caption='Carbon Monoxide Dehydrogenase/Acetyl-CoA Synthase' scene='Insert optional scene name here' />
-
<Structure load='3ki4' size='300' color='white' frame='true' align='right' caption='X-Ray Diffraction image at 2.1Å of Cholix Toxin from Vibrio Cholerae' />
 
 +
=== '''Introduction''' ===
 +
==='''Structure'''===
-
== Cholix Toxin from ''Vibrio Cholerae ''==
+
==='''Mechanism of Action'''===
-
The [http://en.wikipedia.org/wiki/Crystal_structure crystal structure] of the purified form of ''' Cholix Toxin''' or '''CT''' was determined in 1995.It is an oligomeric bacterial protein found to be made up of six individual <scene name='Sandbox_Reserved_496/Secondary_structure/1'>subunits, </scene> one single α-subunit and 5 individual β- subunits.The α-subunit makes up what is known as the enzymatic portion of the protein while the 5 copies of the β-subunit are responsible for the binding to the ligand receptor. The toxin binds highly specifically and tightly to a [http://en.wikipedia.org/wiki/GM1_gangliosidoses GM1 gangliosides] on the surface of the host's cells. In this X-Ray Diffraction image we can see the <scene name='Sandbox_Reserved_496/Binding_site/1'>catalytic</scene> site, which in this case has been complexed with an allosteric inhibitor (red and yellow space filling atoms). Recent studies have indicated several amino acid <scene name='Sandbox_Reserved_496/Critical_amino_acids/2'> residues </scene> located proximally to the active site which are critical for enzymatic activity. Specifically, site directed mutagenesis indicated that when altered, the mutation results in a termination of the proteins toxicity, rendering it essentially harmless.
+
-
 
+
==='''Possible Applications'''===
-
 
+
-
 
+
-
 
+
-
 
+
-
 
+
-
 
+
-
 
+
-
 
+
-
 
+
-
 
+
-
 
+
-
 
+
-
 
+
-
 
+
-
== '''Toxin Mechanism''' ==
+
-
Once secreted, the B subunit will bind to GM1 gangliosides on the surface. After binding takes place, the whole complex is engulfed by the cell and a portion known as the CTA1 chain is detached after reduction of a disulfide bridge. The new endosome is moved to the Golgi, where it is recognized by the endoplasmic reticulum, unfolded and delivered to the membrane, where the Endoplasmic Reticulum-oxidase - "'''Ero1'''" triggers the release of the excised A1 protein (through Oxidation) of '''protein disulfide isomerase complex'''. As A1 moves from the ER into the cytoplasm it refolds and avoids further reduction.[1]
+
-
 
+
-
 
+
-
The A1 fragment catalyses '''ADP ribosylation''' from NAD to the regulatory component (G-protein) of adenylate cyclase, two main components in an important signal transduction pathway. The newly formed A1-Gαs complex is then unable to hydrolyse properly leaving the GTP bound to the Gαs subunit, which results in the transducer being continually activated. Increased adenylate cyclase activity increases cyclic AMP (cAMP concentration increases more than 100 times normal concentrations) synthesis. This can cause rapid fluid loss from the intestines, up to 2 liters per hour, leading to severe dehydration and diarrhea.
+
-
 
+
-
 
+
-
 
+
-
[[Image:Cholera_Mechanism.jpg]]
+
-
 
+
-
 
+
-
 
+
-
 
+
-
 
+
-
 
+
-
 
+
-
 
+
-
 
+
-
 
+
-
 
+
-
== '''Uses & Potential Benefits''' ==
+

Revision as of 17:53, 1 May 2012

Bold text

This Sandbox is Reserved from 13/03/2012, through 01/06/2012 for use in the course "Proteins and Molecular Mechanisms" taught by Robert B. Rose at the North Carolina State University, Raleigh, NC USA. This reservation includes Sandbox Reserved 451 through Sandbox Reserved 500.
To get started:
  • Click the edit this page tab at the top. Save the page after each step, then edit it again.
  • Click the 3D button (when editing, above the wikitext box) to insert Jmol.
  • show the Scene authoring tools, create a molecular scene, and save it. Copy the green link into the page.
  • Add a description of your scene. Use the buttons above the wikitext box for bold, italics, links, headlines, etc.

More help: Help:Editing

For more help, look at this link: http://www.proteopedia.org/wiki/index.php/Help:Getting_Started_in_Proteopedia


Contents

Bifunctional Carbon Monoxide Dehydrogenase/Acetyl-CoA Synthase (CODH/ACS)

Carbon Monoxide Dehydrogenase/Acetyl-CoA Synthase

Drag the structure with the mouse to rotate


Introduction

Structure

Mechanism of Action

Possible Applications
Retrieved from "http://52.214.119.220/wiki/index.php/Sandbox_Reserved_496"
Personal tools