1acc
From Proteopedia
(New page: 200px<br /> <applet load="1acc" size="450" color="white" frame="true" align="right" spinBox="true" caption="1acc, resolution 2.1Å" /> '''ANTHRAX PROTECTIVE A...) |
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| - | [[Image:1acc.gif|left|200px]]<br /> | + | [[Image:1acc.gif|left|200px]]<br /><applet load="1acc" size="350" color="white" frame="true" align="right" spinBox="true" |
| - | <applet load="1acc" size=" | + | |
caption="1acc, resolution 2.1Å" /> | caption="1acc, resolution 2.1Å" /> | ||
'''ANTHRAX PROTECTIVE ANTIGEN'''<br /> | '''ANTHRAX PROTECTIVE ANTIGEN'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Protective antigen (PA) is the central component of the three-part protein | + | Protective antigen (PA) is the central component of the three-part protein toxin secreted by Bacillus anthracis, the organism responsible for anthrax. After proteolytic activation on the host cell surface, PA forms a membrane-inserting heptamer that translocates the toxic enzymes, oedema factor and lethal factor, into the cytosol. PA, which has a relative molecular mass of 83,000 (M(r) 83K), can also translocate heterologous proteins, and is being evaluated for use as a general protein delivery system. Here we report the crystal structure of monomeric PA at 2.1 A resolution and the water-soluble heptamer at 4.5 A resolution. The monomer is organized mainly into antiparallel beta-sheets and has four domains: an amino-terminal domain (domain 1) containing two calcium ions and the cleavage site for activating proteases; a heptamerization domain (domain 2) containing a large flexible loop implicated in membrane insertion; a small domain of unknown function (domain 3); and a carboxy-terminal receptor-binding domain (domain 4). Removal of a 20K amino-terminal fragment from domain 1 allows the assembly of the heptamer, a ring-shaped structure with a negatively charged lumen, and exposes a large hydrophobic surface for binding the toxic enzymes. We propose a model of pH-dependent membrane insertion involving the formation of a porin-like, membrane-spanning beta-barrel. |
==About this Structure== | ==About this Structure== | ||
| - | 1ACC is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_anthracis Bacillus anthracis] with CA as [http://en.wikipedia.org/wiki/ligand ligand]. The following page contains interesting information on the relation of 1ACC with [[http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb28_1.html Anthrax Toxin]]. Full crystallographic information is available from [http:// | + | 1ACC is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_anthracis Bacillus anthracis] with <scene name='pdbligand=CA:'>CA</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. The following page contains interesting information on the relation of 1ACC with [[http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb28_1.html Anthrax Toxin]]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ACC OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Bacillus anthracis]] | [[Category: Bacillus anthracis]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Liddington, R | + | [[Category: Liddington, R C.]] |
[[Category: Petosa, C.]] | [[Category: Petosa, C.]] | ||
[[Category: CA]] | [[Category: CA]] | ||
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[[Category: toxin]] | [[Category: toxin]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:43:03 2008'' |
Revision as of 09:43, 21 February 2008
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ANTHRAX PROTECTIVE ANTIGEN
Overview
Protective antigen (PA) is the central component of the three-part protein toxin secreted by Bacillus anthracis, the organism responsible for anthrax. After proteolytic activation on the host cell surface, PA forms a membrane-inserting heptamer that translocates the toxic enzymes, oedema factor and lethal factor, into the cytosol. PA, which has a relative molecular mass of 83,000 (M(r) 83K), can also translocate heterologous proteins, and is being evaluated for use as a general protein delivery system. Here we report the crystal structure of monomeric PA at 2.1 A resolution and the water-soluble heptamer at 4.5 A resolution. The monomer is organized mainly into antiparallel beta-sheets and has four domains: an amino-terminal domain (domain 1) containing two calcium ions and the cleavage site for activating proteases; a heptamerization domain (domain 2) containing a large flexible loop implicated in membrane insertion; a small domain of unknown function (domain 3); and a carboxy-terminal receptor-binding domain (domain 4). Removal of a 20K amino-terminal fragment from domain 1 allows the assembly of the heptamer, a ring-shaped structure with a negatively charged lumen, and exposes a large hydrophobic surface for binding the toxic enzymes. We propose a model of pH-dependent membrane insertion involving the formation of a porin-like, membrane-spanning beta-barrel.
About this Structure
1ACC is a Single protein structure of sequence from Bacillus anthracis with as ligand. The following page contains interesting information on the relation of 1ACC with [Anthrax Toxin]. Full crystallographic information is available from OCA.
Reference
Crystal structure of the anthrax toxin protective antigen., Petosa C, Collier RJ, Klimpel KR, Leppla SH, Liddington RC, Nature. 1997 Feb 27;385(6619):833-8. PMID:9039918
Page seeded by OCA on Thu Feb 21 11:43:03 2008
