Sandbox Reserved 982

This Sandbox is Reserved from 15-Jan-2015, through 30-May-2015 for use in the course "Biochemistry" taught by Jason Telford at the Maryville University. This reservation includes Sandbox Reserved 977 through Sandbox Reserved 986.

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

Shiga Toxin

spinqualitylabelsall models Crystal Structure for Shiga Toxin (1R4Q) Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural Highlights Crystal Structure of Shiga Toxin Stx is composed of two main subunits labeled A and B. The A subunit bonds noncovalently to the B subunit. The A subunit is 293 amino acids long with its active site being glutamic acid 167. Studies have shown that the first 239 residues are essential for the enzymatic activity of the A subunit. The B subunit is a pentamer that resembles a star and can be divided into five identical subunits. Each of the subunits is 69 amino acids in length. The purpose of the B subunit is to bind to globotriaosylceramide (GB3) which is a glycosphingolipid that resides on the surface of some Eukaryotic cells. Each monomer of the B subunit has three binding sites for GB3 making the protein very potent (Melton-Celsa 2013). Function The pathway of stx entering a cell begins with the B subunit’s binding to GB3. Once this occurs, the A subunit disconnects from the B subunit and enters the cell through endocytosis. Using retrograde transport the A subunit passes through the Golgi apparatus and the rough endoplasmic reticulum. In the rough endoplasmic reticulum, the A subunit is cleaved into two parts called A1 and A2. A2 is degraded, but A1 freely enters the cytosol (Sandvig 2000). Once in the cytosol, A1 acts as an N-glycosidase, which is an enzyme that hydrolyzes bonds that link sugars. With this enzymatic activity, A1 removes adenines from the 28S RNA of the 60S ribosomal subunit (Melton-Celsa 2013). This inhibits protein synthesis and ultimately leads to cell death. Disease and It's Pathogenesis This is a sample scene created with SAT to TextToBeDisplayed by Group, and another to make a transparent representation of the protein. You can make your own scenes on SAT starting from scratch or loading and editing one of these sample scenes.