Sandbox Reserved 818

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
(→Mechanism of pertussis toxin)
(→Mechanism of pertussis toxin)
Line 36: Line 36:
labeled in blue : catalytic residues (His35, Glu129) <br />
labeled in blue : catalytic residues (His35, Glu129) <br />
-
The ADP-ribosylation of trimeric G proteins occurs on a '''cystein residue''' in the ''C-terminal part of the α-subunit''. For that, the donor substrate used by PTX is NAD<sup>+</sup>
+
The ADP-ribosylation of trimeric G proteins occurs on a '''cystein residue''' in the ''C-terminal part of the α-subunit''. For that, the donor substrate used by PTX is '''NAD<sup>+</sup>''' and the acceptor substrate binds to the toxin through '''residues 180-219''' in the ''C-terminal region of S1''. These residues show indeed a high affinity for the G protein and are involved in the catalysis of the ADP-ribosylation.
==Toxic effects of pertussis toxin==
==Toxic effects of pertussis toxin==

Revision as of 11:33, 5 January 2014

This Sandbox is Reserved from 06/12/2018, through 30/06/2019 for use in the course "Structural Biology" taught by Bruno Kieffer at the University of Strasbourg, ESBS. This reservation includes Sandbox Reserved 1480 through Sandbox Reserved 1543.
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

Image:1prt.png

Template:STRUCTURE 1prt

Contents

PERTUSSIS TOXIN

About this Structure

1prt is a 12 chain structure with sequence from Bordetella pertussis. The September 2005 RCSB PDB Molecule of the Month feature on Cholera Toxin by David S. Goodsell is 10.2210/rcsb_pdb/mom_2005_9. Full crystallographic information is available from OCA.


Introduction

blabla


Binding of PTX to its cellular targets

piou piou

Toxin entry and trafficking in target cells

Mechanism of pertussis toxin

Pertussis toxin (PTX) acts on target cells through its A protomer which contains the enzymatically active S1 subunit.
This subunit catalyzes ADP-ribosylation of the α-subunit of trimeric G proteins, which disturbs functions of the target cells and therefore lead to various biological effects.

In facts, substrates of PTX are regulators of the membrane-bound adenylate cyclase. These G proteins bind GTP in order to transduce signals in the cell. When ADP-ribosylation by PTX occurs, the downregulation of the adenylate cyclase activity is inhibited.
This inhibition leads to increase cAMP levels in cells, which explains the amount of biological activities of the toxin.

-> picture of the active site of the S1 subunit
labeled in green : key residues surrounding the NAD-binding cavity (Arg9, Trp26, Cys41)
labeled in blue : catalytic residues (His35, Glu129)

The ADP-ribosylation of trimeric G proteins occurs on a cystein residue in the C-terminal part of the α-subunit. For that, the donor substrate used by PTX is NAD+ and the acceptor substrate binds to the toxin through residues 180-219 in the C-terminal region of S1. These residues show indeed a high affinity for the G protein and are involved in the catalysis of the ADP-ribosylation.

Toxic effects of pertussis toxin

See Also

Reference

  • Stein PE, Boodhoo A, Armstrong GD, Cockle SA, Klein MH, Read RJ. The crystal structure of pertussis toxin. Structure. 1994 Jan 15;2(1):45-57. PMID:8075982
Retrieved from "http://52.214.119.220/wiki/index.php/Sandbox_Reserved_818"
Personal tools