1pju
From Proteopedia
(New page: 200px<br /><applet load="1pju" size="450" color="white" frame="true" align="right" spinBox="true" caption="1pju, resolution 2.15Å" /> '''Unbound form of Toma...) |
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| - | [[Image:1pju.jpg|left|200px]]<br /><applet load="1pju" size=" | + | [[Image:1pju.jpg|left|200px]]<br /><applet load="1pju" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1pju, resolution 2.15Å" /> | caption="1pju, resolution 2.15Å" /> | ||
'''Unbound form of Tomato Inhibitor-II'''<br /> | '''Unbound form of Tomato Inhibitor-II'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The Potato II (Pot II) family of proteinase inhibitors plays important | + | The Potato II (Pot II) family of proteinase inhibitors plays important roles in the constitutive and inducible defense of plants against predation by a wide range of pests. The structural basis of inhibition by a multidomain Pot II family inhibitor was revealed recently by the structure of the ternary complex between the two-headed tomato inhibitor-II (TI-II) and two molecules of subtilisin Carlsberg. Here we report the 2.15-A resolution crystal structure of the unbound form of TI-II that reveals significant conformational flexibility in the absence of bound proteinase molecules. The four independent copies of unbound TI-II in the asymmetric unit of the unit cell display a range of different conformations when compared with the bound form of the inhibitor, most strikingly in the orientations of the inhibitory domains and in the conformations of the reactive site loops. One of the two linker segments (residues 74 to 79) between the two domains as well as the adjacent beta-strand in Domain I (residues 80-85) is well ordered in all four copies of the unbound inhibitor, even though this region appeared to be disordered in the structure of the ternary complex. Conformational flexibility seen in the reactive site loops of unbound TI-II suggests a mechanism by which the inhibitor can balance the need for tight binding with the need for broad inhibitory function. |
==About this Structure== | ==About this Structure== | ||
| - | 1PJU is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Solanum_lycopersicum Solanum lycopersicum] with SO4 as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1PJU is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Solanum_lycopersicum Solanum lycopersicum] with <scene name='pdbligand=SO4:'>SO4</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1PJU OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Solanum lycopersicum]] | [[Category: Solanum lycopersicum]] | ||
| - | [[Category: Barrette-Ng, I | + | [[Category: Barrette-Ng, I H.]] |
| - | [[Category: Cherney, M | + | [[Category: Cherney, M M.]] |
[[Category: Ghani, U.]] | [[Category: Ghani, U.]] | ||
| - | [[Category: James, M | + | [[Category: James, M N.G.]] |
| - | [[Category: Ng, K | + | [[Category: Ng, K K.S.]] |
[[Category: Pearce, G.]] | [[Category: Pearce, G.]] | ||
| - | [[Category: Ryan, C | + | [[Category: Ryan, C A.]] |
[[Category: SO4]] | [[Category: SO4]] | ||
[[Category: proteinase inhibitor]] | [[Category: proteinase inhibitor]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:29:38 2008'' |
Revision as of 12:29, 21 February 2008
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Unbound form of Tomato Inhibitor-II
Overview
The Potato II (Pot II) family of proteinase inhibitors plays important roles in the constitutive and inducible defense of plants against predation by a wide range of pests. The structural basis of inhibition by a multidomain Pot II family inhibitor was revealed recently by the structure of the ternary complex between the two-headed tomato inhibitor-II (TI-II) and two molecules of subtilisin Carlsberg. Here we report the 2.15-A resolution crystal structure of the unbound form of TI-II that reveals significant conformational flexibility in the absence of bound proteinase molecules. The four independent copies of unbound TI-II in the asymmetric unit of the unit cell display a range of different conformations when compared with the bound form of the inhibitor, most strikingly in the orientations of the inhibitory domains and in the conformations of the reactive site loops. One of the two linker segments (residues 74 to 79) between the two domains as well as the adjacent beta-strand in Domain I (residues 80-85) is well ordered in all four copies of the unbound inhibitor, even though this region appeared to be disordered in the structure of the ternary complex. Conformational flexibility seen in the reactive site loops of unbound TI-II suggests a mechanism by which the inhibitor can balance the need for tight binding with the need for broad inhibitory function.
About this Structure
1PJU is a Single protein structure of sequence from Solanum lycopersicum with as ligand. Full crystallographic information is available from OCA.
Reference
Unbound form of tomato inhibitor-II reveals interdomain flexibility and conformational variability in the reactive site loops., Barrette-Ng IH, Ng KK, Cherney MM, Pearce G, Ghani U, Ryan CA, James MN, J Biol Chem. 2003 Aug 15;278(33):31391-400. Epub 2003 Jun 4. PMID:12788916
Page seeded by OCA on Thu Feb 21 14:29:38 2008
