1olp: Difference between revisions

Revision as of 04:00, 3 May 2008

ALPHA TOXIN FROM CLOSTRIDIUM ABSONUM

OverviewOverview

Clostridium absonum phospholipase C (Caa) is a 42.7 kDa protein, which shows 60% amino acid sequence identity with the Clostridium perfringens phospholipase C, or alpha-toxin (Cpa), and has been isolated from patients suffering from gas gangrene. We report the cloning and sequencing, purification, characterisation and crystal structure of the Caa enzyme. Caa had twice the phospholipid-hydrolysing (lecithinase) activity, 1.5 times the haemolytic activity and over seven times the activity towards phosphatidylcholine-based liposomes when compared with Cpa. However, the Caa enzyme had a lower activity than Cpa to the free (i.e. not in lipid bilayer) substrate para-nitrophenylphosphorylcholine, towards sphingomyelin-based liposomes and showed half the cytotoxicity. The lethal dose (LD(50)) of Caa in mice was approximately twice that of Cpa. The crystal structure of Caa shows that the 72-93 residue loop is in a conformation different from those of previously determined open-form alpha-toxin structures. This conformational change suggests a role for W84 in membrane binding and a possible route of entry into the active site along a hydrophobic channel created by the re-arrangement of this loop. Overall, the properties of Caa are compatible with a role as a virulence-determinant in gas gangrene caused by C.absonum.

About this StructureAbout this Structure

1OLP is a Single protein structure of sequence from Clostridium sardiniense. Full crystallographic information is available from OCA.

ReferenceReference

Clostridium absonum alpha-toxin: new insights into clostridial phospholipase C substrate binding and specificity., Clark GC, Briggs DC, Karasawa T, Wang X, Cole AR, Maegawa T, Jayasekera PN, Naylor CE, Miller J, Moss DS, Nakamura S, Basak AK, Titball RW, J Mol Biol. 2003 Oct 31;333(4):759-69. PMID:14568535 Page seeded by OCA on Sat May 3 04:00:13 2008

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA

@@ Line 1: / Line 1: @@
 [[Image:1olp.jpg|left|200px]]
- {{Structure
+<!--
-|PDB= 1olp |SIZE=350|CAPTION= <scene name='initialview01'>1olp</scene>, resolution 2.50&Aring;
+The line below this paragraph, containing "STRUCTURE_1olp", creates the "Structure Box" on the page.
-|SITE= <scene name='pdbsite=AC1:Zn+Binding+Site+For+Chain+D'>AC1</scene>
+You may change the PDB parameter (which sets the PDB file loaded into the applet)
-|LIGAND= <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene>
+or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
-|ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Phospholipase_C Phospholipase C], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.4.3 3.1.4.3] </span>
+or leave the SCENE parameter empty for the default display.
-|GENE=
+-->
-|DOMAIN=
+{{STRUCTURE_1olp|  PDB=1olp  |  SCENE=  }}
-|RELATEDENTRY=
-|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1olp FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1olp OCA], [http://www.ebi.ac.uk/pdbsum/1olp PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1olp RCSB]</span>
-}}
 '''ALPHA TOXIN FROM CLOSTRIDIUM ABSONUM'''
@@ Line 28: / Line 25: @@
 [[Category: Basak, A K.]]
 [[Category: Briggs, D C.]]
-[[Category: calcium binding]]
+[[Category: Calcium binding]]
-[[Category: gas gangrene determinant]]
+[[Category: Gas gangrene determinant]]
-[[Category: hydrolase]]
+[[Category: Hydrolase]]
-[[Category: membrane binding]]
+[[Category: Membrane binding]]
-[[Category: zinc phospholipase c]]
+[[Category: Zinc phospholipase c]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May  3 04:00:13 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 22:47:01 2008''