1kho
From Proteopedia
(New page: 200px<br /><applet load="1kho" size="450" color="white" frame="true" align="right" spinBox="true" caption="1kho, resolution 2.4Å" /> '''Crystal Structure Ana...) |
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| - | [[Image:1kho.jpg|left|200px]]<br /><applet load="1kho" size=" | + | [[Image:1kho.jpg|left|200px]]<br /><applet load="1kho" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1kho, resolution 2.4Å" /> | caption="1kho, resolution 2.4Å" /> | ||
'''Crystal Structure Analysis of Clostridium perfringens alpha-Toxin Isolated from Avian Strain SWCP'''<br /> | '''Crystal Structure Analysis of Clostridium perfringens alpha-Toxin Isolated from Avian Strain SWCP'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Clostridium perfringens alpha-toxin is a 370-residue, zinc-dependent, phospholipase C that is the key virulence determinant in gas gangrene. It | + | Clostridium perfringens alpha-toxin is a 370-residue, zinc-dependent, phospholipase C that is the key virulence determinant in gas gangrene. It is also implicated in the pathogenesis of sudden death syndrome in young animals and necrotic enteritis in chickens. Previously characterized alpha-toxins from different strains of C. perfringens are almost identical in sequence and biochemical properties. We describe the cloning, nucleotide sequencing, expression, characterization, and crystal structure of alpha-toxin from an avian strain, SWan C. perfringens (SWCP), which has a large degree of sequence variation and altered substrate specificity compared to these strains. The structure of alpha-toxin from strain CER89L43 has been previously reported in open (active site accessible to substrate) and closed (active site obscured by loop movements) conformations. The SWCP structure is in an open-form conformation, with three zinc ions in the active site. This is the first example of an open form of alpha-toxin crystallizing without the addition of divalent cations to the crystallization buffer, indicating that the protein can retain three zinc ions bound in the active site. The topology of the calcium binding site formed by residues 269, 271, 336, and 337, which is essential for membrane binding, is significantly altered in comparison with both the open and closed alpha-toxin structures. We are able to relate these structural changes to the different substrate specificity and membrane binding properties of this divergent alpha-toxin. This will provide essential information when developing an effective vaccine that will protect against C. perfringens infection in a wide range of domestic livestock. |
==About this Structure== | ==About this Structure== | ||
| - | 1KHO is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Clostridium_perfringens Clostridium perfringens] with ZN as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1KHO is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Clostridium_perfringens Clostridium perfringens] with <scene name='pdbligand=ZN:'>ZN</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KHO OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Clostridium perfringens]] | [[Category: Clostridium perfringens]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Basak, A | + | [[Category: Basak, A K.]] |
[[Category: Justin, N.]] | [[Category: Justin, N.]] | ||
| - | [[Category: Moss, D | + | [[Category: Moss, D S.]] |
| - | [[Category: Titball, R | + | [[Category: Titball, R W.]] |
[[Category: ZN]] | [[Category: ZN]] | ||
[[Category: c-terminal beta-sheet]] | [[Category: c-terminal beta-sheet]] | ||
[[Category: n-terminal alpha-helix]] | [[Category: n-terminal alpha-helix]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:34:17 2008'' |
Revision as of 11:34, 21 February 2008
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Crystal Structure Analysis of Clostridium perfringens alpha-Toxin Isolated from Avian Strain SWCP
Overview
Clostridium perfringens alpha-toxin is a 370-residue, zinc-dependent, phospholipase C that is the key virulence determinant in gas gangrene. It is also implicated in the pathogenesis of sudden death syndrome in young animals and necrotic enteritis in chickens. Previously characterized alpha-toxins from different strains of C. perfringens are almost identical in sequence and biochemical properties. We describe the cloning, nucleotide sequencing, expression, characterization, and crystal structure of alpha-toxin from an avian strain, SWan C. perfringens (SWCP), which has a large degree of sequence variation and altered substrate specificity compared to these strains. The structure of alpha-toxin from strain CER89L43 has been previously reported in open (active site accessible to substrate) and closed (active site obscured by loop movements) conformations. The SWCP structure is in an open-form conformation, with three zinc ions in the active site. This is the first example of an open form of alpha-toxin crystallizing without the addition of divalent cations to the crystallization buffer, indicating that the protein can retain three zinc ions bound in the active site. The topology of the calcium binding site formed by residues 269, 271, 336, and 337, which is essential for membrane binding, is significantly altered in comparison with both the open and closed alpha-toxin structures. We are able to relate these structural changes to the different substrate specificity and membrane binding properties of this divergent alpha-toxin. This will provide essential information when developing an effective vaccine that will protect against C. perfringens infection in a wide range of domestic livestock.
About this Structure
1KHO is a Single protein structure of sequence from Clostridium perfringens with as ligand. Full crystallographic information is available from OCA.
Reference
The first strain of Clostridium perfringens isolated from an avian source has an alpha-toxin with divergent structural and kinetic properties., Justin N, Walker N, Bullifent HL, Songer G, Bueschel DM, Jost H, Naylor C, Miller J, Moss DS, Titball RW, Basak AK, Biochemistry. 2002 May 21;41(20):6253-62. PMID:12009886
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