1si9
From Proteopedia
(New page: 200px<br /><applet load="1si9" size="450" color="white" frame="true" align="right" spinBox="true" caption="1si9, resolution 2.27Å" /> '''Boiling stable prote...) |
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| - | [[Image:1si9.jpg|left|200px]]<br /><applet load="1si9" size=" | + | [[Image:1si9.jpg|left|200px]]<br /><applet load="1si9" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1si9, resolution 2.27Å" /> | caption="1si9, resolution 2.27Å" /> | ||
'''Boiling stable protein isolated from Populus tremula'''<br /> | '''Boiling stable protein isolated from Populus tremula'''<br /> | ||
==Overview== | ==Overview== | ||
| - | We previously reported on a new boiling stable protein isolated from aspen | + | We previously reported on a new boiling stable protein isolated from aspen plants (Populus tremula), which we named SP1. SP1 is a stress-related protein with no significant sequence homology to other stress-related proteins. It is a 108-amino-acid hydrophilic polypeptide with a molecular mass of 12.4 kDa (Wang, W. X., Pelah, D., Alergand, T., Shoseyov, O., and Altman, A. (2002) Plant Physiol. 130, 865-875) and is found in an oligomeric form. Preliminary electron microscopy studies and matrix-assisted laser desorption ionization time-of-flight mass spectrometry experiments showed that SP1 is a dodecamer composed of two stacking hexamers. We performed a SDS-PAGE analysis, a differential scanning calorimetric study, and crystal structure determination to further characterize SP1. SDS-PAGE indicated a spontaneous assembly of SP1 to one stable oligomeric form, a dodecamer. Differential scanning calorimetric showed that SP1 has high thermostability i.e. Tm of 107 degrees C (at pH 7.8). The crystal structure of SP1 was initially determined to 2.4 A resolution by multi-wavelength anomalous dispersion method from a crystal belonging to the space group I422. The phases were extended to 1.8 A resolution using data from a different crystal form (P21). The final refined molecule includes 106 of the 108 residues and 132 water molecules (on average for each chain). The R-free is 20.1%. The crystal structure indicated that the SP1 molecule has a ferredoxin-like fold. Strong interactions between each two molecules create a stable dimer. Six dimers associate to form a ring-like-shaped dodecamer strongly resembling the particle visualized in the electron microscopy studies. No structural similarity was found between the crystal structure of SP1 and the crystal structure of other stress-related proteins such as small heat shock proteins, whose structure has been already determined. This structural study further supports our previous report that SP1 may represent a new family of stress-related proteins with high thermostability and oligomerization. |
==About this Structure== | ==About this Structure== | ||
| - | 1SI9 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Populus_tremula Populus tremula] with GOL as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1SI9 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Populus_tremula Populus tremula] with <scene name='pdbligand=GOL:'>GOL</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1SI9 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Shoseyov, O.]] | [[Category: Shoseyov, O.]] | ||
[[Category: Sofer, O.]] | [[Category: Sofer, O.]] | ||
| - | [[Category: Wolf, S | + | [[Category: Wolf, S G.]] |
[[Category: GOL]] | [[Category: GOL]] | ||
[[Category: boiling-soluble]] | [[Category: boiling-soluble]] | ||
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[[Category: stress]] | [[Category: stress]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:01:50 2008'' |
Revision as of 13:01, 21 February 2008
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Boiling stable protein isolated from Populus tremula
Overview
We previously reported on a new boiling stable protein isolated from aspen plants (Populus tremula), which we named SP1. SP1 is a stress-related protein with no significant sequence homology to other stress-related proteins. It is a 108-amino-acid hydrophilic polypeptide with a molecular mass of 12.4 kDa (Wang, W. X., Pelah, D., Alergand, T., Shoseyov, O., and Altman, A. (2002) Plant Physiol. 130, 865-875) and is found in an oligomeric form. Preliminary electron microscopy studies and matrix-assisted laser desorption ionization time-of-flight mass spectrometry experiments showed that SP1 is a dodecamer composed of two stacking hexamers. We performed a SDS-PAGE analysis, a differential scanning calorimetric study, and crystal structure determination to further characterize SP1. SDS-PAGE indicated a spontaneous assembly of SP1 to one stable oligomeric form, a dodecamer. Differential scanning calorimetric showed that SP1 has high thermostability i.e. Tm of 107 degrees C (at pH 7.8). The crystal structure of SP1 was initially determined to 2.4 A resolution by multi-wavelength anomalous dispersion method from a crystal belonging to the space group I422. The phases were extended to 1.8 A resolution using data from a different crystal form (P21). The final refined molecule includes 106 of the 108 residues and 132 water molecules (on average for each chain). The R-free is 20.1%. The crystal structure indicated that the SP1 molecule has a ferredoxin-like fold. Strong interactions between each two molecules create a stable dimer. Six dimers associate to form a ring-like-shaped dodecamer strongly resembling the particle visualized in the electron microscopy studies. No structural similarity was found between the crystal structure of SP1 and the crystal structure of other stress-related proteins such as small heat shock proteins, whose structure has been already determined. This structural study further supports our previous report that SP1 may represent a new family of stress-related proteins with high thermostability and oligomerization.
About this Structure
1SI9 is a Single protein structure of sequence from Populus tremula with as ligand. Full crystallographic information is available from OCA.
Reference
The structural basis of the thermostability of SP1, a novel plant (Populus tremula) boiling stable protein., Dgany O, Gonzalez A, Sofer O, Wang W, Zolotnitsky G, Wolf A, Shoham Y, Altman A, Wolf SG, Shoseyov O, Almog O, J Biol Chem. 2004 Dec 3;279(49):51516-23. Epub 2004 Sep 14. PMID:15371455
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