1jzb
From Proteopedia
(New page: 200px<br /><applet load="1jzb" size="450" color="white" frame="true" align="right" spinBox="true" caption="1jzb, resolution 2.81Å" /> '''Crystal Structure of...) |
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| - | [[Image:1jzb.gif|left|200px]]<br /><applet load="1jzb" size=" | + | [[Image:1jzb.gif|left|200px]]<br /><applet load="1jzb" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1jzb, resolution 2.81Å" /> | caption="1jzb, resolution 2.81Å" /> | ||
'''Crystal Structure of Variant 2 Scorpion Toxin from Centruroides sculpturatus Ewing'''<br /> | '''Crystal Structure of Variant 2 Scorpion Toxin from Centruroides sculpturatus Ewing'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Centruroides sculpturatus Ewing variant 2 toxin (CsE-v2) is a neurotoxin | + | Centruroides sculpturatus Ewing variant 2 toxin (CsE-v2) is a neurotoxin isolated from the venom of a scorpion native to the Arizona desert. The structure of CsE-v2 was solved in two different crystal forms using a combination of molecular replacement and multiple isomorphous replacement techniques. Crystals of CsE-v2 display a temperature-dependent, reversible-phase transition near room temperature. At lower temperature the space group changes from P3(2)21 to P3(1)21 with an approximate doubling of the C-axis. The small-cell structure, which has one molecule per asymmetric unit, has an R factor of 0.229 at 2.8 A resolution. The large-cell structure has two molecules per asymmetric unit and was refined at 2.2 A resolution to an R factor of 0.255. CsE-v2 is a rigid, compact structure with four intrachain disulfide bonds. The structure is similar to other long-chain beta neurotoxins, and the largest differences occur in the last six residues. The high-resolution structure of CsE-v2 corrects an error in the reported C-terminal sequence; the terminal tripeptide sequence is Ser 64-Cys 65-Ser 66 rather than Ser 64-Ser 65-Cys 66. Comparison of CsE-v2 with long-chain alpha toxins reveals four insertions and one deletion, as well as additional residues at the N and C termini. Structural alignment of alpha and beta toxins suggests that the primary distinguishing feature between the two classes is the length of the loop between the second and third strands in a three-strand beta sheet. The shorter loop in alpha toxins exposes a critical lysine side chain, whereas the longer loop in beta toxins buries the corresponding basic residue (either arginine or lysine). |
==About this Structure== | ==About this Structure== | ||
| - | 1JZB is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Centruroides_sculpturatus Centruroides sculpturatus]. Full crystallographic information is available from [http:// | + | 1JZB is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Centruroides_sculpturatus Centruroides sculpturatus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1JZB OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Centruroides sculpturatus]] | [[Category: Centruroides sculpturatus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Cook, W | + | [[Category: Cook, W J.]] |
| - | [[Category: Ealick, S | + | [[Category: Ealick, S E.]] |
| - | [[Category: Watt, D | + | [[Category: Watt, D D.]] |
[[Category: Zell, A.]] | [[Category: Zell, A.]] | ||
[[Category: crystal structure]] | [[Category: crystal structure]] | ||
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[[Category: scorpion toxin]] | [[Category: scorpion toxin]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:28:24 2008'' |
Revision as of 11:28, 21 February 2008
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Crystal Structure of Variant 2 Scorpion Toxin from Centruroides sculpturatus Ewing
Overview
Centruroides sculpturatus Ewing variant 2 toxin (CsE-v2) is a neurotoxin isolated from the venom of a scorpion native to the Arizona desert. The structure of CsE-v2 was solved in two different crystal forms using a combination of molecular replacement and multiple isomorphous replacement techniques. Crystals of CsE-v2 display a temperature-dependent, reversible-phase transition near room temperature. At lower temperature the space group changes from P3(2)21 to P3(1)21 with an approximate doubling of the C-axis. The small-cell structure, which has one molecule per asymmetric unit, has an R factor of 0.229 at 2.8 A resolution. The large-cell structure has two molecules per asymmetric unit and was refined at 2.2 A resolution to an R factor of 0.255. CsE-v2 is a rigid, compact structure with four intrachain disulfide bonds. The structure is similar to other long-chain beta neurotoxins, and the largest differences occur in the last six residues. The high-resolution structure of CsE-v2 corrects an error in the reported C-terminal sequence; the terminal tripeptide sequence is Ser 64-Cys 65-Ser 66 rather than Ser 64-Ser 65-Cys 66. Comparison of CsE-v2 with long-chain alpha toxins reveals four insertions and one deletion, as well as additional residues at the N and C termini. Structural alignment of alpha and beta toxins suggests that the primary distinguishing feature between the two classes is the length of the loop between the second and third strands in a three-strand beta sheet. The shorter loop in alpha toxins exposes a critical lysine side chain, whereas the longer loop in beta toxins buries the corresponding basic residue (either arginine or lysine).
About this Structure
1JZB is a Single protein structure of sequence from Centruroides sculpturatus. Full crystallographic information is available from OCA.
Reference
Structure of variant 2 scorpion toxin from Centruroides sculpturatus Ewing., Cook WJ, Zell A, Watt DD, Ealick SE, Protein Sci. 2002 Mar;11(3):479-86. PMID:11847271
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