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.


1mdt

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
Line 1: Line 1:
-
[[Image:1mdt.gif|left|200px]]
+
[[Image:1mdt.png|left|200px]]
<!--
<!--
Line 12: Line 12:
-
==Overview==
+
{{ABSTRACT_7833808}}
-
The structure of toxic monomeric diphtheria toxin (DT) was determined at 2.3 A resolution by molecular replacement based on the domain structures in dimeric DT and refined to an R factor of 20.7%. The model consists of 2 monomers in the asymmetric unit (1,046 amino acid residues), including 2 bound adenylyl 3'-5' uridine 3' monophosphate molecules and 396 water molecules. The structures of the 3 domains are virtually identical in monomeric and dimeric DT; however, monomeric DT is compact and globular as compared to the "open" monomer within dimeric DT (Bennett MJ, Choe S, Eisenberg D, 1994b, Protein Sci 3:0000-0000). Detailed differences between monomeric and dimeric DT are described, particularly (1) changes in main-chain conformations of 8 residues acting as a hinge to "open" or "close" the receptor-binding (R) domain, and (2) a possible receptor-docking site, a beta-hairpin loop protruding from the R domain containing residues that bind the cell-surface DT receptor. Based on the monomeric and dimeric DT crystal structures we have determined and the solution studies of others, we present a 5-step structure-based mechanism of intoxication: (1) proteolysis of a disulfide-linked surface loop (residues 186-201) between the catalytic (C) and transmembrane (T) domains; (2) binding of a beta-hairpin loop protruding from the R domain to the DT receptor, leading to receptor-mediated endocytosis; (3) low pH-triggered open monomer formation and exposure of apolar surfaces in the T domain, which insert into the endosomal membrane; (4) translocation of the C domain into the cytosol; and (5) catalysis by the C domain of ADP-ribosylation of elongation factor 2.
+
==About this Structure==
==About this Structure==
1MDT is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Corynephage_beta Corynephage beta]. The following page contains interesting information on the relation of 1MDT with [[http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb69_1.html Cholera Toxin]]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1MDT OCA].
1MDT is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Corynephage_beta Corynephage beta]. The following page contains interesting information on the relation of 1MDT with [[http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb69_1.html Cholera Toxin]]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1MDT OCA].
- 
-
==Reference==
 
-
Refined structure of monomeric diphtheria toxin at 2.3 A resolution., Bennett MJ, Eisenberg D, Protein Sci. 1994 Sep;3(9):1464-75. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/7833808 7833808]
 
[[Category: Cholera Toxin]]
[[Category: Cholera Toxin]]
[[Category: Corynephage beta]]
[[Category: Corynephage beta]]
Line 26: Line 22:
[[Category: Eisenberg, D.]]
[[Category: Eisenberg, D.]]
[[Category: Toxin]]
[[Category: Toxin]]
-
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 00:55:21 2008''
+
 
 +
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Jun 26 17:42:36 2008''

Revision as of 14:42, 26 June 2008

Image:1mdt.png

Template:STRUCTURE 1mdt

THE REFINED STRUCTURE OF MONOMERIC DIPHTHERIA TOXIN AT 2.3 ANGSTROMS RESOLUTION


Template:ABSTRACT 7833808

About this Structure

1MDT is a Single protein structure of sequence from Corynephage beta. The following page contains interesting information on the relation of 1MDT with [Cholera Toxin]. Full crystallographic information is available from OCA.

Page seeded by OCA on Thu Jun 26 17:42:36 2008

Proteopedia Page Contributors and Editors (what is this?)

OCA

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